A 10-minute walk west of Kusatsu's Yubatake, at the far end of Sainokawara Park, lies one of Japan's largest open-air baths. Around 500 m² of pool brims with strongly acidic water, open to the surrounding forest. Snow in winter, fresh green in summer, illuminations at night. There are no washing stations — this is purely for soaking.
One cedar 'nyuto tegata' pass (¥1,500) admits you to any three of the rotenburo at Kurokawa's 26-odd ryokan. Valid for six months, and one of the three stickers can be spent on food or souvenirs instead. Most inns accept bathers roughly 8:30–21:00, but hours vary and some close for cleaning or when full. Buy the pass at any ryokan or the association office 'Kaze no Ya'.
A thatched communal bath on the shore of Lake Kinrin. Unstaffed — drop ¥300 in the box at the door. Changing area and bath share one room; an indoor pool and a half-open pool facing the lake, and it is mixed bathing with clear water and little screening, so it's a challenge for women. Right in busy central Yufuin, but quiet at the 10 am opening.
A terraced open-air bath along a mountain stream that holds 200 people, with bluish-white strongly acidic sulfur water. Open late April to late November only; closed in winter. Summer starlight sessions at night.
At 1,800 m, one of Japan's highest onsen. Milky water with some of the country's highest sulfur content, across nine tubs. Day use 10:00–17:00; prices rise in peak season.
An open-air-only bath at the edge of the Pacific. One of Japan's oldest springs, mentioned in the 8th-century Nihon Shoki; on rough days sea spray reaches the tubs. No roof, no wash stations.
A five-minute ride down a 42-degree cable car to the bottom of the Iya gorge, where a self-flowing bath sits beside the river. Day use 7:30–17:00, cable car included. A member of the Secret Onsen Preservation Society.
A milky open-air bath on a hillside above Beppu Bay. Thatched 'yunohana huts' where bath salts are harvested — a national cultural property — line the grounds and can be visited free. Hell-steamed food too.
An onsen on an island 15 minutes' drive from Naha Airport. From the open-air bath you watch the sun set over the Kerama sea and planes land right in front of you. ¥2,000 with towels, open from 6 am — ideal last soak before your flight.
The heart of Kusatsu, where 4,000 litres a minute cascade down wooden channels. The Yukemuri-tei pavilion beside it is a free 24-hour foot bath, lit up at night. Start your visit here.
A public bath that is entirely open-air, on the Hida River. No indoor pool — six outdoor tubs including a waterfall shower, box steam and pot baths. Gero's silky pH 8.9 water with a river breeze.
An inn famous for spring water that turns cobalt blue on certain days. A wide open-air bath with views of Mt. Yufu and silica-rich water that feels like lotion, for ¥800.
A large hotel whose top-floor 'sky' open-air baths look over the Noboribetsu hills. Day use in two windows — 5–9 am and 11 am–7 pm — for ¥1,200. A little away from the main strip, so quieter.
The signature of Beppu's giant hilltop hotel: a five-tiered open-air bath cascading toward Beppu Bay, spectacular at night and dawn. Day tickets include the swimsuit-friendly outdoor spa pool 'Aqua Garden'.
A long-established inn on the southern rim of the Yufuin basin. Its vast 'Gomusō-no-yu' open-air bath looks straight at Mt. Yufu across the valley. Day-use reception is short (10 am–2 pm), but on weekdays you may have it to yourself.
A free foot bath in an actual river of hot spring water flowing out of Ōyunuma pond, at the end of a forest boardwalk. The perfect finish to a Jigokudani walk. Daylight hours; the trail may close in deep snow.
A huge boulder-lined mixed open-air bath on the Gamata riverbed, looking up at the Northern Alps and a suspension bridge. Open only late April to the end of October; swimwear or bathing gowns allowed. Pay a cleaning donation of about ¥300.
The onsen bathhouse of the Laforet resort on the hills above Shuzenji. A big indoor bath overlooking the Amagi range, an open-air bath among birdsong, and a sauna. Day use 12–9 pm, ¥940; free shuttle from Shuzenji Station.
Five minutes' drive beyond the village in Oku-Kurokawa, this inn's riverside open-air bath 'Yūkoku-no-yu' is often called the finest in Kurokawa. Day use 10 am–3 pm, ¥600 (or with the ¥1,500 hopping pass); private baths ¥2,500/50 min until 8 pm.
At 1,800 m in Manza, four private sources feed eight open-air pools of milky, yellow and clear water — the famous 'Sekitei' rock-garden baths. Mixed bathing, but gowns or wrapped towels are required and there is a women-only pool. Day use 11 am–6 pm (last 5 pm), ¥1,700.
Four minutes from Hankyu Arashiyama Station and a short walk from Togetsukyo Bridge, Arashiyama's only dedicated day-use onsen. Mildly alkaline simple spring water in indoor, open-air, silky and sauna baths. Easy to slot between sights, with towel rental so you can come empty-handed. The changing room is small, so avoid peak hours. ¥1,200 weekdays, ¥1,400 weekends and holidays.
A natural open-air bath on the Asahi River gravel bed right below Yubara Dam, where water bubbles up through the riverbed itself — ranked the 'western grand champion' of Japan's rotenburo. Three pools at different temperatures; mixed, free and open 24 hours. Only a simple changing hut, so women are advised to wear a bathing garment (sold and rented in town). Closed Wednesday mornings for cleaning. Photography strictly forbidden.
A wooden toji (therapeutic stay) inn over 200 years old on the Toyosawa River in the Hanamaki-Minami onsen area, once frequented by poet Kenji Miyazawa. Its signature is 'Osawa-no-yu', a mixed open-air bath jutting over the river, with women-only hours. Day bathing from 7 am; ¥700 covers three baths. Many linger for lunch and sake at the 'Yahagi' dining room. Free shuttle from Hanamaki Station.
A day-use-only onsen on the Otaki side of Yoro Valley on the Boso Peninsula, near Awamata Falls. A rotenburo looking over wooded hills and a timber indoor bath hold the dark-tinted alkaline water typical of Boso. Popular after hikes and waterfall walks; towel and robe rental mean you can come empty-handed. Closes early at 18:00; Wednesdays off.
At the southern tip of Nara, directly opposite the Totsukawa Onsen bus center where Japan's longest local bus route (Yagi–Shingu) stops. A small all-timber bathhouse looking down on the Futatsuno dam lake. The whole village has pledged 'free-flowing spring water only', so nothing is recirculated. Free foot bath, hand bath and drinking fountain. Combine with the Kumano Kodo and Tanize suspension bridge.
The closest day onsen to World Heritage Miyajima, on the opposite shore. Every tub looks out over the Seto Inland Sea toward the island: rotenburo, cypress bath, rock bath, sauna and foot bath. Mildly radioactive (radon) simple spring. A natural stop on the way back from Miyajima, with a restaurant serving Seto fish. ¥800 weekdays, open until 22:00.
The source bath of Yamaguchi's oldest hot spring, opened some 600 years ago. Local volunteers rebuilt the aging public bath in 2020; the bathroom sits directly on the spring, so you stand chest-deep in a 1-m pool watching water seep from the bedrock. Around 39°C — made for long soaks. The riverside lounge doubles as a café open to non-bathers. Pair with a stroll through the town redeveloped around Hoshino Resorts' KAI Nagato.
A top-floor panoramic onsen in a resort hotel at Aoshima, Miyazaki's beach district. Large indoor bath, rock rotenburo, waterfall bath and sauna all look down on the Hyuga Sea and Aoshima island; day use is accepted 11:00–22:00. Slightly salty simple spring water. Convenient after Aoshima Shrine, the 'Devil's Washboard' rock formations or a surf session, and 15 minutes by car from Miyazaki Airport. ¥1,100, towels extra.
A ryokan-style day spa on a hill among mandarin groves, away from Yugawara's main street. The draw is a rotenburo with a sweeping view of Sagami Bay, lit up at night. Two bathrooms alternate daily between men and women, and the water is drinkable. Free tatami rest hall and restaurant. ¥1,380; bring a towel. Closed Thursdays except holidays, March and August. Bus from Manazuru or Yugawara Station.
Twenty minutes by train from Aomori, a panoramic bath on the 5th floor of the roadside station at Asamushi Onsen on Mutsu Bay. Big windows frame Yunoshima island and the bay — sunset is the prime slot. Salt- and sulfate-rich water keeps you warm afterwards. Just ¥360, open 7:00–21:00 every day. The ground-floor market sells Aomori souvenirs. Two minutes' walk from Asamushi-Onsen Station.
On a mountainside above the Kofu basin, a spectacular open-air bath with Mt. Fuji and the city lights in view. It opens 'one hour before sunrise', so people arrive in the dark to watch dawn break over Fuji from the water. Of the two bathhouses, 'Acchi-no-yu' is the larger with the better view. ¥900. The deep-fried hot-spring egg from the food stall is a must. Ten minutes by taxi from Yamanashi-shi Station; a feasible day trip from Tokyo.
Five minutes by car from the Kazurabashi vine bridge, the day-use bath of a large hotel at the mouth of the Iya Valley — the biggest bathhouse in Iya, with a rotenburo facing the green gorge, indoor pool and sauna. At ¥1,100 it's a cheaper, later-opening alternative to Hotel Iya Onsen's cable-car bath (¥1,900). 20 minutes by car from Oboke Station. Closed Tuesdays.
Twenty minutes by train from Kyoto, the flagship ryokan of Ogoto Onsen on Lake Biwa's west shore. The top-floor open-air bath 'Yugen Shoyo' overlooks the lake and the Hiei range, with garden rotenburo and more to hop between. pH 9 'beautifying' water. Day use ¥2,000, 11:00–21:30; entry may be limited when busy. Five minutes by shuttle from Ogoto-Onsen Station — a convenient soak after Kyoto sightseeing.
Two hours by train from Tokyo, a day spa right in front of Oarai Sun Beach. The open-air baths — 'Kuroshio' for men, 'Oyashio' for women — look straight out over the Pacific, and the strong salt water from 1,500 m down keeps you warm long after. There's also a carbonated bath. The panoramic restaurant serves seafood from Oarai port. ¥1,000 on weekdays, 10:00–21:30, open daily. Five minutes by taxi from Oarai Station.
Forty minutes by car from Kochi city, a hot-spring inn beside Shoryuji, temple 36 of the Shikoku pilgrimage. It claims Kochi's only high-concentration, high-temperature spring; the golden chloride water is nicknamed 'the heat bath' for how long it keeps you warm. The rotenburo looks over Usa Bay and the Pacific, and there's a free seaside footbath. Day use in two sessions — 5:30–9:00 and 14:00–21:00 — ¥750 on weekdays.
An hour by car from Miyazaki, a resort hotel on a rise in Kitago, Nichinan, ringed by cedar-clad hills. The silky bicarbonate water (around pH 9.5) is known as a 'beauty bath', and the rotenburo looks across the mountains and Nichinan farmland. Day bathing runs a generous 10:00–22:00 — easy to combine with Obi castle town or Udo Shrine. ¥1,200.
About 70 minutes from central Tokyo via the Aqua-Line, a hot-spring inn founded in 1950 on the shore of Lake Kameyama in the Boso hills. Its chocolate-brown 'kuroyu' bicarbonate water — billed as Boso's finest beauty bath — flows freely into a large bath with lake and forest views. Day use 11:30–18:00, ¥1,000 on weekdays; no day bathing Thursdays and Fridays. In autumn pair it with a foliage cruise on the lake.
Next to the Himi Banya-gai seafood market near the port famous for winter yellowtail, a day spa fed by its own well 1,250 m down. The brown, strongly saline water flows freely, and on clear days the rotenburo frames the Tateyama range across Toyama Bay. Open 10:00–23:00, from 7:00 on weekends and holidays. ¥950. The classic routine: kaisen-don or conveyor sushi at the market, then a soak.
A small riverside hotel on the south side of Kinugawa Onsen, five minutes from Tobu World Square Station. While the big hotels stop day bathing around 15:00, this one welcomes walk-ins 9:00–21:00 for ¥700. Its own alkaline sulfur spring (43.6 °C) flows 100% free into a quirky set of baths: a rotenburo made from an actual Kinugawa river-cruise boat, a rock rotenburo, indoor baths and a swimsuit mixed bath. The slightly cool, silky water is highly rated by onsen fans.
An hour by car from central Hiroshima, a city-run lodge at Yuki Onsen, 'Hiroshima's back parlour'. The rotenburo above the clear Minochi River and the timber-lined main bath are all free-flowing, with a rare mildly radioactive (radon) spring. ¥750 per visit or ¥1,000 for an all-day pass. Open till 21:00 in summer, 20:00 in winter. Direct buses run from Hiroshima city — an easy hot-spring break between Miyajima and the Peace Park.
The source bath of Ryujin Onsen, counted with Yunokawa and Kawanaka among Japan's 'three beauty baths'. It stands on the Hidaka River deep in the Kii mountains, with a cypress indoor bath and a rock rotenburo overlooking the stream. The silky bicarbonate water is famous for leaving skin smooth. ¥800, 7:00–21:00, open daily. An hour by car from Koyasan via the Koya-Ryujin Skyline, or about 80 minutes by bus from Kii-Tanabe.
About 90 minutes from Nagoya by train and car, an inn on the Sankai coast at the southern tip of the Chita Peninsula. Day visitors can use the rotenburo and main bath with sweeping views of Ise Bay — sunset over the water is the highlight. The chloride spring of Minami-Chita, Aichi's most abundant hot-spring area, keeps you warm afterwards. ¥800, 11:00–21:00; towels sold for ¥200. Pair with the beach in summer or fugu dinners in winter.
A lakeside ryokan drawing 'Taiko Onsen' water from the site of Hideyoshi's Nagahama Castle. The rust-red iron-rich spring keeps you warm long after, and the rotenburo looks out over Lake Biwa to Chikubu Island. Day use 11:00–14:30 and 15:00–20:00, ¥1,500 including bath and face towels. Seven minutes' walk from Nagahama Station — easy to pair with the Kurokabe Square old town. About an hour from Kyoto by rapid train.
Thirty minutes by car from Naha Airport, a natural hot spring in a hilltop resort hotel in Nanjo, southern Okinawa. Golden water from strata about 5.4 million years old carries roughly 80% the salinity of seawater and is prized for warmth and skin care. The panoramic bath and rotenburo overlook Nakagusuku Bay and the Chinen Peninsula. Open 6:30–23:00 daily; ¥2,200 including a towel set and loungewear. Pair with Sefa Utaki or Cape Chinen.
Five minutes by car from the Kazurabashi vine bridge, this popular Iya inn is famous for its 'sky open-air bath' reached by private cable car. Day bathing (¥1,200) runs 10:30–16:00; the goemon cauldron baths are for overnight guests only. A free sky footbath on the viewing deck is spectacular on mornings with a sea of clouds. With Hotel Iya Onsen it forms Iya's pair of 'cable-car onsen', ideal for a break while touring the valley.
A town-run day spa attached to the Echizen roadside station on the coast famous for Echizen crab. The open-air bath juts toward the Sea of Japan, facing sunsets over the horizon and, after dark, the squid-boat lanterns ('isaribi') that give it its name. Silky 'beauty water', an indoor bath and sauna for a wallet-friendly ¥520. Busy in winter with visitors pairing a soak with a crab lunch.
About 90 minutes from Akihabara via the Tsukuba Express, a day spa on the slopes of Mt. Tsukuba. The open-air bath opens onto a cliff with the whole Kantō plain below—the classic post-hike or post-cable-car soak. Alkaline simple spring water around pH 9 leaves skin smooth. ¥1,100 weekdays, ¥1,300 weekends; reservable private baths too. Check the calendar for closure days.
A solitary inn on the Hinoji River in the Shimanto headwaters. Its viscous, highly alkaline water has been revered as a healing spring since the Edo period, and a day soak is a modest ¥700. Enjoy the open-air bath above the stream or book a private bath. Open late, 10:30–21:00, and 30 minutes by car from Kubokawa Station—ideal after canoeing or cycling the Shimanto.
A day spa on the Hinosawa stream in Oku-Nagatoro, named after Suisen-ji, the final temple of the Chichibu 34 Kannon pilgrimage. Mangan Falls tumbles right in front of the open-air bath—stunning in fresh green and autumn colour. pH 9.4 alkaline water with a pronounced silky feel. ¥980 weekdays (¥750 after 17:00), ¥1,200 weekends. Combine with the Nagatoro river boats or Mt. Hodo.
Three minutes by car from Yamanakako IC, a day spa with Mt. Fuji rising straight ahead of the open-air bath. Highly alkaline (pH 10.3) yet gentle on the skin. Two open-air baths—stone and cypress—plus a lie-down bath, jets and sauna for ¥900. On winter weekends (Dec–Feb) it opens at dawn so you can watch the peak blush red at sunrise, the 'benifuji' of its name. 30 minutes from Fujisan Station on the Fujikko-gō loop bus.
A city-run day bath on the shore of the Unazuki dam lake. From the lakeside open-air bath you can watch the Kurobe Gorge trolley train crawl along the far cliff — a favourite with railway fans. Just ¥510 including shampoo and hairdryers, with silky mildly alkaline water. Open only from late April to early December; closed in winter. Five minutes from Unazuki-Onsen Station by the free 'EMU' shuttle or car.
A lone inn at 1,300 m, the last stop in the Nasu hot-spring range. Spring water gushes out behind the building in such volume that it forms a river, dammed into the vast outdoor 'Kawa-no-yu' — nothing else like it in Japan. Mixed bathing since the inn's founding, but bathing wear is included so beginners can relax. Day use is limited to three hours (reception 11:30–14:30), ¥1,300 with face towel and bathing wear. The outdoor bath closes in bad weather or for cleaning, so phone ahead. Autumn colour and snow seasons are the draw.
An all-glass communal bath on the shore of Lake Shibayama in Katayamazu, part of the Kaga onsen cluster, designed by architect Yoshio Taniguchi. The lake-facing 'Kata-no-yu' and garden-facing 'Mori-no-yu' swap between men and women on odd and even days; for ¥500 you get the Hakusan peaks and the lake to yourself. The salty chloride water keeps you warm long after. Open from 6:00 to 22:00, with a café upstairs (closed Thursdays) selling onsen eggs. About 10 min by bus from Kaga-Onsen Station.
A long-established bath theme park on a hillside three minutes' walk from Hankyu Minoh Station in northern Osaka. The panoramic main bath and open-air tubs look out over the Osaka plain, and with stone-slab baths, a manga corner, games, stage shows and a buffet you can spend the whole day in lounge wear. Admission ¥1,813 on weekdays (¥2,253 weekends), dropping to a ¥922 evening rate after 17:00. Open until 23:45 — popular with hikers coming back from the Minoh Falls autumn foliage trail.
The highlight of any Gonō Line journey: a lone inn famous nationwide for its 'seaside open-air bath' set right at the water's edge of the Sea of Japan. Iron-rich chloride water, rust-red and cloudy, seems to merge with sea and sky. Day use is ¥600 — the seaside bath 8:00–16:00 (last entry 15:30), the main-building indoor 'Kogane-no-yu' 8:00–20:00. The mixed outdoor bath allows bathing wear (rental fee); a women-only outdoor bath sits alongside. Sunset soaks are for overnight guests only, so stay if you want one of Japan's 100 best sunsets from the tub.
At Kawayu, where 73°C spring water bubbles up through the bed of the Ōtō River, a giant outdoor bath is created every December to February by damming the river. Roughly 50 by 15 metres — big enough for 'a thousand people', as the name says — it's tempered to perfection by the river's cold flow. Free (donation box), 6:30–22:00, swimwear required, open to everyone. Bathing is suspended in bad weather or high water and opening dates shift from year to year. In summer you can dig your own pool in the gravel. Combine with Yunomine and Watarase for the three Hongu baths.
A day bath inside a public inn 15 minutes by ferry from Kagoshima port and 8 minutes' walk from Sakurajima port. Water rises at 51°C from a magma layer 1,000 m below, clouded rust-brown with iron, and flows freely through a bath hall looking across Kinkō Bay to the city. ¥460, 11:00–21:00 — a bargain after touring the volcano or the lava seaside trail. The free 100-metre Lava Nagisa Park footbath is within walking distance. Operations may be affected by volcanic alert levels.
A large ryokan 10 minutes by car from Hakodate Airport and 3–4 minutes' walk from the Yunokawa-Onsen tram stop. From the 11th-floor panoramic bath hall and 'sky open-air bath' you look over the city, the Tsugaru Strait and, at night, squid-boat lights and the Mt Hakodate skyline — even planes landing at the airport when the timing is right. Day use ¥1,200 in two sessions, 6:00–9:00 and 13:00–21:00, including the top-floor sauna. Private baths ¥3,300 per 50 minutes (reserve). Easy to combine with the morning market and Goryōkaku.
A large lakeside hotel at the centre of the Toyako onsen strip. The top-floor panoramic bath and open-air tubs take in the lake, Nakajima island and Mt Yōtei beyond — and from late April to the end of October you can watch the nightly 20:45 fireworks from the water. Day use ¥1,200 on weekdays, ¥1,500 on weekends, in two sessions: 7:00–10:00 and 13:00–21:00. The chloride water holds heat well. A paid shuttle from Sapporo Station (reservation required) makes it a handy base for Shikotsu-Tōya National Park.
An inn with its own spring midway along the Yukawa gorge, where the ryokan of Higashiyama Onsen line the river 10 minutes by car from central Aizu-Wakamatsu. Day visitors get the riverside open-air bath facing a waterfall and the main bath for ¥1,100 including a small towel, 13:00–20:00. Private panoramic baths (¥1,650) and lunch packages are also offered. With 1,300 years of history, Higashiyama was the retreat of artists such as Takehisa Yumeji and poet Yosano Akiko — a natural finish to a day at Tsuruga Castle and the Byakkotai sites on Iimoriyama. Reception hours may shorten when busy.
A view ryokan at the tip of the Nishiura peninsula in Gamagōri, built right on Mikawa Bay. The two bath halls, Fusumi-no-yu and Kōsai-no-yu, open straight onto the sea, with sunsets and night lights the main event. Day use 11:00–15:00 ¥1,500 with towel, or 15:00–19:00 ¥1,800 with bath towel. The top-floor private panoramic open-air bath is ¥2,200 per 50 minutes for day visitors (reserve). About an hour from Nagoya on the Meitetsu line, with a shuttle from Nishiura Station. Day bathing is suspended on some dates — check 'today's status' on the official site.
A public resort inn in the pine woods of the Echizen-Kaga Coast park, five minutes by car from the Tōjinbō cliffs. The glass-walled indoor bath and open-air Araiso-no-yu face the Sea of Japan and its sunsets, with cherry blossom in spring. Day use 11:30–15:00 (last entry), ¥900; closed to day visitors on Tuesdays for maintenance. Well stocked with shampoo and conditioner; towels are rented (¥310) or bring your own. Eight minutes by car from Mikuni-Minato Station — an easy stop between Tōjinbō and an Echizen crab lunch (Nov–Mar).
An onsen on the fifth floor of a resort hotel facing Emerald Beach, seven minutes' walk from the Churaumi Aquarium. Chloride water is drawn from Jurassic strata some 200 million years old, and the open-air bath looks across cobalt-blue sea to Ie Island. Two bathrooms — one with a dry sauna, one with steam — alternate daily between men and women, with cold plunge and outdoor rest area. Day use ¥2,150 including towel set, 6:00–10:00 and 15:00–23:00. A rare genuine hot spring in Okinawa, best enjoyed in the late afternoon after the aquarium.
A resort hotel on the waterfront of Tomonoura, the old tide-waiting port near Fukuyama. The top-floor bath hall 'Tenkū' and its open-air tub look across to Sensuijima and the calm Seto Inland Sea; the water is a natural radium spring. A löyly-capable sauna and steam sauna were added in 2023. Day use 11:00–18:00 (last entry 17:00), ¥1,600, with free bath towels. Private open-air baths 'Sansan' and 'Tōtō' are ¥5,500 per 50 minutes (reserve). 30 minutes by bus from Fukuyama Station to Tomokō; pair with the Edo-period streets and the stone lantern.
A ryokan built out over Lake Tōgō, known as the 'inn on the lake': lobby and baths are surrounded by water on three sides, and the open-air Kōsuke-yu sits almost level with the surface. Free-flowing simple spring water. Day bathing runs on an irregular basis, roughly 11:00–14:00, ¥1,000 cash only — phone the same day to confirm. Private open-air baths are ¥1,650 per 45 minutes, booked by phone from 9:00 that morning. 18 minutes by bus from Kurayoshi Station to the Hawai Onsen stop. No restaurant inside, so eat in the onsen town or at the Enchōen roadside station.
A roadside-station onsen on the hill of Shōdoshima Olive Park, right beside the Greek windmill made famous by film shoots. Big windows frame olive groves and the Seto Inland Sea; there are a herb bath, waterfall shower and sauna. The water is a radioactive (radon) spring. Owing to staff shortages, hours are shortened to 15:00–20:00 (last entry 19:30) from 17 July 2026 until further notice; ¥1,000, towel set rental ¥200. Closed all day Wednesday, and the onsen only on Thursday (holidays vary). Five minutes by car from Kusakabe port, ten from Ikeda port. Pair with a stroll around the park and the adjacent Olive Beach at island dusk.
A long-established hotel on the cliffs of the Izura coast, the scenic spot beloved of art historian Okakura Tenshin. The main building and the Taikansō annex flank the Rokkakudō pavilion; day bathers use Taikan-no-yu in the annex. The open-air bath, refurbished in 2012, sits right above the Pacific — free-flowing spring water, the horizon and the sound of breaking waves. The indoor hall also looks out to sea through big windows. Day use in two sessions, 11:00–15:00 (last entry 14:30) and 18:00–21:00 (last entry 20:30), ¥1,100. Closure days are irregular, so check the official notice page. Five minutes by car from JR Ōtsukō Station; combine with the Tenshin Memorial Museum and Rokkakudō.
One of Tōhoku's highest hot springs, at 1,126 m on the northern slopes of Mt Kurikoma. Some 6,000 litres a minute flow like a stream; the strongly acidic alum-vitriol water (pH around 2) carries white mineral flakes and tingles on the skin. The famous big open-air Dainichi-yu is an open, rock-backed pool; day use 6:00–21:00 (until 20:00 on Wednesdays), ¥900. The indoor baths and the 'oiran' steam bath run 9:00–16:00. Because of the altitude, the road and the onsen close in winter (early November to early May). About 95 minutes by bus from Ichinoseki Station to the Sukawa Onsen terminus; it is also the Kurikoma trailhead, busiest in autumn colour season (late Sept–early Oct).
A design hotel on the headland at Cape Ashizuri, Shikoku's southernmost point, renewed in 2024. It holds one of the source wells of the Ashizuri hot-spring cluster — a natural radon spring, mildly alkaline, with a legend linking it to Kōbō Daishi — enjoyed in an open-air bath overlooking the Pacific, two indoor tubs and a Shimanto-cypress sauna. Sunsets into the horizon and the night sky are the draw. Day use 15:00–21:00 (last entry 20:30), ¥1,100 including bathing tax. Closed Tuesday to Thursday (with exceptions in peak season), so confirm ahead. About 90 minutes by bus from Nakamura Station, or an hour by car from Shimanto city. Combine with the cape lookout, the aquarium and the free Manjirō foot bath.
A mountain hot spring in the temple-gate village of Kurama, about 30 minutes from central Kyoto on the Eizan railway, home of the tengu legends. The open-air Hōroku-yu sits in a cedar grove facing the Kitayama hills and becomes a snow-viewing bath in winter. The simple hydrogen-sulphide water carries a faint whiff of sulphur that suits the mountain air. The open-air-only course is ¥1,500 weekdays / ¥1,600 weekends (towels extra); the full day course with indoor bath, open-air bath, sauna, lounge, towels and robe is around ¥2,600 on weekdays. Open 10:00–21:00 every day, no reservation. Ten minutes on foot from Kurama Station or by free shuttle. The classic way to end a visit to Kurama-dera or the hike over to Kibune — for anyone who wants a genuine onsen in Kyoto.
An open-air-only public bath on the gravel banks of the Gamata River at Tochio Onsen in the Okuhida valley. The rock-ringed men's and women's pools have no screen on the river side, so the rushing Gamata and the Northern Alps fill the view — starry skies at night, snow scenes in winter, wild Okuhida all year. Free-flowing simple spring water; there are changing huts but no reception — drop a donation (about ¥300) in the wooden box at the entrance. Open 8:00–22:00 (from 12:00 Mon, Wed and Fri for cleaning); no closing days, but suspended when the river is high. Bring a towel. An easy stop between the Shinhotaka Ropeway and Hirayu, or a night soak for anyone staying in Tochio's inns.
A day-use-only onsen on the slopes of the Minou range above Tanushimaru in Kurume, fruit-picking country an hour by car from Fukuoka city. The panoramic open-air bath looks over the Chikugo plain and river, most popular at dusk and after dark for the lights. The water is a skin-smoothing alkaline simple spring. Besides the indoor and open-air baths there are family baths (indoor ¥2,500 per hour, with open-air tub ¥3,600), and the attached café is loved for weekday lunches and desserts. ¥880; open 10:00–20:00 (main bath last entry 19:30), closed Thursdays and the 1st and 3rd Wednesday (open on holidays). Ten minutes by car from JR Tanushimaru Station, 15 from Asakura IC. A fine finish to a Fukuoka-area drive with Harazuru Onsen or Yanagawa.
A solitary forest inn five minutes by car from central Kurokawa, where the only sound is the headwaters of the Chikugo River. On roughly 10,000 m² of grounds sit the mixed open-air Moyai-no-yu and the women-only Shiki-no-yu, fed free-flowing from two private springs; the indoor bath has a faint blue tint. Day use covers the open-air baths only, 08:30–21:00, ¥600 for adults, and Kurokawa's 'nyūtō tegata' bath-hopping pass (¥1,500 for three baths) is accepted, so pairing it with inns in the village is the classic plan. There is a free rest corner after bathing. Closures are irregular — phone ahead.
A mid-sized hotel on the lakeside promenade of Lake Tōya, and a rarity here: day bathing for just ¥600. The 'Tono-yu / Hime-yu' baths have granite-clad open-air tubs, bubble baths and a sauna, and the bicarbonate–chloride–sulphate water keeps you warm long after. Day use is accepted 13:00–21:00. From late April to the end of October, the Lake Tōya long-run fireworks go up over the water every night from 20:45, and a stroll along the shore before a soak is a lovely routine. With neighbouring resort hotels charging ¥1,000+, this is the value pick. About 20 minutes by bus from Tōya Station to 'Tōyako Onsen', then 5 minutes on foot.
About 12 minutes on foot from Murodō terminal, the hub of the Tateyama-Kurobe Alpine Route, this inn at 2,410 m is Japan's highest hot-spring lodging. Milky acidic sulphur water piped from Jigokudani flows 100% free, and outside the window is another world: the 3,000-metre Tateyama range and the volcanic lake Mikurigaike. The bath is indoor only; day use 09:00–16:00, ¥1,100 for adults. The café's blueberry soft-serve and curry are favourites. Open only during the mountain season, mid-April to late November; closed in winter. Especially busy during the Snow Corridor (Apr–Jun) and autumn colours (late Sep–early Oct). With the altitude and strong water, keep your soak short.
A lone inn of the Japan Association of Secluded Hot Springs, deep in Hachimantai National Park amid beech and oak forest. The open-air bath is an unusual greenish milky white — free-flowing simple hydrogen-sulphide water — with a mixed outdoor bath, a women-only outdoor bath and separate indoor baths; from the rotenburo you can see the steam of Japan's first geothermal power station. Day use 08:30–19:00 (last entry 18:00), ¥700 for adults, or ¥900 with hall rest 10:00–15:00. Open year-round, and the snow-buried outdoor bath in winter is the highlight. About 1 h 50 min by Iwate Kenpoku bus from Morioka Station to the Matsukawa Onsen terminus.
A hot-spring hotel on the cliffs of Inubōsaki, the easternmost point of the Kantō region. Perched on a cape jutting into the Pacific, its rock rotenburo and European-style open-air bath 'Opia' look out to the horizon and the Inubōsaki lighthouse; on New Year's Day you can watch Japan's earliest sunrise from the tub. The day-use course runs 12:00–19:00 (leave by 20:00), ¥1,500 for a 90-minute stay including bath towel, face towel and toiletries, so come empty-handed. Open daily (special pricing at Obon and New Year). Seven minutes on foot from Inubō Station on the Chōshi Electric Railway; combine with a seafood lunch in Chōshi and the 'Hill Where the Earth Looks Round' observatory.
Near the village office of Totsukawa, Japan's largest village, this is the public bath of Tōsenji Onsen, the oldest spring in the village. True to Totsukawa — the first place in Japan to declare all its baths 100% free-flowing — the roughly 60°C sulphur water is cooled without dilution and left to overflow. As the name suggests, the big draw is the streamside open-air bath at the bottom of a long staircase, where you soak facing a small waterfall; the water runs hot. There are also an indoor bath and sauna. ¥800 for adults, open 08:30–20:00, closed Thursdays. The lunch-only diner is known for its 'dam curry'. The nearby Izumi-yu is ¥100 cheaper, but come here for the waterfall. A remote spot about 3 h 40 min from Yamato-Yagi Station on Japan's longest local bus route.
A public hot-spring lodge at the mouth of Nakatsu Gorge in Niyodogawa, Kōchi — the land of 'Niyodo blue'. The all-cypress open-air bath, rebuilt in 2019, sits right in the gorge, so you soak facing fresh greenery, autumn colour or snow depending on the season. The water is an alkaline simple sulphur spring, heated from a cold source. Day use 11:00–21:00 (last bath 20:00), ¥700 for adults, rising to ¥800 in cherry-blossom and autumn seasons, Golden Week, Obon and New Year. Closed Tuesdays (next day if a holiday) and two Wednesdays a month. The classic plan is a one-hour return walk along the gorge trail to Uryū Falls followed by a bath and a set meal of local produce in the restaurant. About 1 h 15 min by car from Kōchi city.
The communal bath of Kawaji Onsen, upstream of Kinugawa on the clear Ojika River. An old cure spa — 'burns to Kinugawa, wounds to Kawaji' went the saying — it uses its own mildly alkaline spring 100% free-flowing with no chlorination. Besides separate indoor and open-air baths there is a mixed rock bath open to the river, where you soak in lukewarm water facing the stream and hills (bathing garments allowed). A low-temperature sauna, private bath (¥4,000 / 50 min) and rest room complete it. Adults pay ¥1,000 (¥500 for Nikkō residents); open 10:00–20:00 (last entry 19:30), closed Wednesdays (next day if a holiday; open through Golden Week). Fifteen minutes on foot from Kawaji-Yumoto Station on the Yagan Railway, or about 15 minutes by car from Kinugawa-Onsen Station — easy to combine with Kinugawa.
A town-run bathhouse right in front of Shirara-hama, the famous white-sand beach. Built like an old-fashioned sentō with an attendant's counter, its second-floor bathroom opens through big windows onto the beach, blue sea and sky — a ¥420 view bath you would never expect in a resort. The 66.8°C sodium-chloride 'Suzushi-yu' source flows freely, and the strongly salty water keeps you warm long after. Open 09:00–11:00 and 14:00–21:30 (last entry 21:00; 07:00–09:00 is residents only), closed Thursdays. Soap and shampoo sold for ¥40; no hair dryers. One of Shirahama's 'sotoyu' circuit with Saki-no-yu and Muro-no-yu — locals rinse off the sand after a swim and come straight in. About 15 minutes by bus from Shirahama Station to 'Shirarahama'.
A free, gender-separated open-air bath at the top of Tsubame Onsen, a trailhead village at about 1,100 m on Mt Myōkō. Five minutes up a mountain path from the village you find only a simple plank changing hut and a rock tub, where flakes of 'yunohana' drift in milky sulphur water. Known as a 'triple beauty bath' for combining sulphur, bicarbonate and sulphate, it faces the flanks of Myōkō. Free of charge from sunrise to sunset, open April to November (closed in winter; boots needed while snow lingers); no bathing on Monday and Friday mornings for cleaning. Fifteen minutes further along the gorge is the mixed 'Kawara-no-yu' (Jul–Nov). No soap allowed and minimal changing space, so follow local etiquette. Walk from the terminus of the bus (about 21 min) from Sekiyama Station.
A large hot-spring hotel in the Ishite River gorge about 8 km inland from Dōgo Onsen. Its great open-air bath 'Suimei-no-yu', billed as one of the largest in western Japan, terraces some 26 tubs down the slope, where you soak in free-flowing alkaline simple sulphur water to the sound of the river — a 'beauty bath' with a clearer sulphur scent than Dōgo. Day use 15:00–20:00 (last entry 19:00), ¥1,100 for adults, irregular closures. The no-reservation private open-air baths 'Yunose' (¥4,400 for 45 min, 2–4 people, towels included) run until 23:00 and suit families or tattooed guests. A cold-spring pool operates in summer. About 50 minutes by bus from Matsuyama Station to 'Okudōgo', or 15 minutes by car from Dōgo Onsen Station.
A big spa resort on the cliffs of Cape Inubō, the first place on Honshū to see the New Year sunrise. The panoramic 'Ichibō-no-yu' main bath sweeps 180 degrees across the Pacific, and with the open-air bath, bedrock-bath rooms and sauna you can watch the sun climb out of the horizon or gaze at Inubōsaki lighthouse while soaking. The water is the sodium-chloride Byōbugaura spring. Adults ¥1,500 on weekdays, ¥1,700 on weekends, holidays and high season (cheaper for morning baths and after 17:00); open 10:00–23:00 (last entry 22:00), and on Saturdays you can stay through to 08:00 the next morning; open every day. Restaurants, banquet rooms, relaxation treatments and an ocean terrace make it a full-day stop to pair with the Chōshi Electric Railway, wet rice crackers and seafood. About 10 minutes on foot from Inubō Station; about an hour by car from Itako IC.
A large lakeside ryokan in the Tōyako Onsen resort whose signature is the top-floor 'sky open-air bath' 32 m above the ground. From the tub you look over Nakajima island in Lake Tōya and, on clear days, to Mt Yōtei beyond; in summer (late April to end of October) the nightly long-run fireworks can be watched from the water. The panoramic main bath also has a sauna. The sodium-calcium-chloride water keeps you warm long after. Day bathing: adults ¥1,200, children ¥600, reception 13:00–19:00 (entry until 18:00), from 14:30 on one Tuesday a month. Towel hire ¥300; 100 free parking spaces. About 20 minutes by Dōnan bus from JR Tōya Station to 'Tōyako Onsen', then 5 minutes on foot; about 2 hours by car from Sapporo. Combine with the lake cruise or the Usuzan Ropeway.
The flagship hotel of Manza Onsen, which at 1,800 m is among the highest hot-spring resorts in Japan reachable by car all year. Perched on a rise, its famous 'Komakusa-no-yu' open-air bath juts from the mountainside so you soak in milky sulphur water while gazing at a sea of clouds, the Jōshin'etsu ranges and, in winter, unbroken snow — literally a bath above the clouds. Besides separate men's and women's sections there is a mixed zone where a wrap towel is worn, making this one of the few Manza inns where mixed bathing is possible. The sulphur content is among Japan's highest and the scent lingers after. Day bathing: adults ¥1,500, children ¥750, reception 11:00–16:00 (bath entry until 15:00), face towel included (bath towel hire ¥300). Weekdays are far quieter than weekends. About 2 hours by Seibu bus from Karuizawa Station, or about 40 minutes by bus from Manza-Kazawaguchi Station; direct ski-slope access in winter.
A day-use bathhouse right beside the Shinhotaka Ropeway base at the trailhead into the Northern Alps. Descended from a mountain hut, it is unusual in having two different springs — a simple spring and a bicarbonate spring — each served free-flowing. The open-air bath, with the murmur of the Gamata River and the rock peaks of Kasa-ga-take and Shakujō-dake in view, fills with hikers coming off the mountain and sightseers back from the ropeway. Adults ¥1,000, children ¥500; open 09:00–18:00 (last entry one hour before closing), irregular closing days. There is a rest room and a restaurant serving Okuhida fare such as Hida beef and soba. About 90 minutes by bus from Takayama Nōhi Bus Center to 'Shinhotaka Onsen', then 2 minutes on foot; parking for 11 cars (pay car parks nearby).
A day-use bathhouse among the vineyards and peach orchards of Makioka in Yamanashi city, cherished by onsen fans as one of the prefecture's finest 'fresh from the source' springs. About 500 litres a minute of 42°C alkaline simple water wells up naturally and goes straight into the tubs — no heating, no dilution, no recirculation — so fresh water overflows constantly at the spout. The feel is silky; from the cypress indoor bath and the rock open-air bath you can sometimes see Mt Fuji across the Kōfu basin. Adults ¥700 for up to two hours, children ¥500 (four hours with tatami-hall rest ¥1,300; all day ¥1,800); open 10:00–21:00 (last entry 20:15), closed Tuesdays and the New Year period. A restaurant serves hōtō noodles and tempura, and Erin-ji temple and the local wineries are close. About 25 minutes by car from Katsunuma IC or 15 minutes by taxi from JR Yamanashi-shi Station.
A hot-spring hotel on the banks of the Yoshino River in the Ōboke–Koboke gorge, where the water has carved through 200-million-year-old rock. The strongly alkaline simple spring — locals say it makes skin toner unnecessary — leaves skin smooth, and the gorge-facing main bath and open-air bath look out over the Koboke rapids, said to be Japan's wildest, and the mountainsides in their seasonal colours. Day bathing: adults ¥700, children ¥350, 12:00–21:00 (last entry 20:00); open daily, but on Saturdays, holidays and group-booking days it may close from 15:00, so check ahead. A convenient base for the Ōboke sightseeing boats, the yōkai museum and the drive to the Iya vine bridge; about 15 minutes on foot from JR Ōboke Station (pick-up available). Soap provided, towels for a fee.
A village-run day spa inside the Soni Kōgen Farm Garden at the foot of the Soni plateau, on Nara's eastern edge, where the pampas-grass meadows turn gold in autumn. The sodium-bicarbonate water is remarkably slippery and lives up to its 'beauty bath' reputation, leaving skin silky. The indoor hall has a free-flowing source tub, and the open-air bath looks out to the rock peaks of Kabuto-dake and Yoroi-dake and across the highland (a wood bathroom and a stone bathroom alternate weekly between men and women). Adults ¥900, children ¥500; open 11:00–21:00 (until 20:30 December–March; last entry one hour before), closed Wednesdays (open if a holiday, then closed the next day) and over New Year. A craft brewery, farm shop and restaurant share the site; it gets very busy in pampas season (October–November). About 45 minutes by bus from Nabari Station; about 1 h 50 min by car from Osaka.
The highest hot-spring inn in Tōhoku, at 1,400 m near the top of the Hachimantai Aspite Line. It opens only from Golden Week to late October; in winter it is buried in snow. Five mixed open-air baths scattered down the slope (plus a women-only open-air bath and separate indoor baths) are fed by sulphur water bubbling up directly through the ground, milky white, and the trademark is smearing the mud from the bottom on your skin as a 'mud pack'. Below spread Mt Iwate and a sea of forest; at dawn, cloud seas and sunrise — truly a bath above the clouds. Simple sulphur water at temperatures from tepid to hot. Day bathing: adults ¥650, children ¥350, with a long 08:00–18:00 window, busy with hikers back from the Hachimantai summit trail. The open-air baths are mixed, so bathing garments and wrap towels are allowed. About 2 hours by bus from Morioka Station or 40 minutes by car from Matsuo-Hachimantai IC. Mobile reception is poor.
A hot-spring inn on a rise above the Chikugo River in Ukiha, Fukuoka, whose pH 8.7 alkaline simple-sulphur water is so silky people say it feels like bathing in skin lotion. Chikugogawa Onsen lies across the river from Harazuru, a quiet designated health resort, and this inn actively welcomes day bathers. Besides the main and open-air baths there are characterful private family baths — 'Stone', 'Rock', even one with a slide — at ¥2,500 for 60 minutes, booked at the desk on the day; the inn states that guests with tattoos may use the private baths only. Day bathing: adults ¥800, children ¥600, 13:00–21:00, closed Wednesdays plus irregular days. The Harazuru–Chikugo River area is known for cormorant fishing and fruit picking, and many families drop in on the way home from the orchards. About 5 minutes by taxi from JR Chikugo-Ōishi Station or 3 minutes by car from Haki IC.
A day-use hot spring at the heart of the Hiruzen highlands in northern Okayama, 500–600 m up. Its great appeal is the open-air bath, where you feel the highland breeze and look out over Jersey-cattle pastures and the three Hiruzen peaks through the seasons — cool in summer, autumn colour, snow-viewing in winter. The alkaline simple water is gentle on the skin, and the facility covers the basics: main bath, jet bath, sauna and open-air bath. Adults ¥740, children ¥420; open 10:00–22:00 (until 21:00 December–March; last entry 30 minutes before), closed Wednesdays (next day if a holiday; open during Obon and Golden Week). About 20 minutes by car from Hiruzen IC or 60 minutes by bus from JR Chūgoku-Katsuyama Station. Combine with Hiruzen yakisoba, Jersey soft-serve and a drive toward Mt Daisen. 100 parking spaces.
A public lodge in the Mitsugi countryside, the 'back parlour' of Onomichi, the port town of slopes, temples and cats. The natural spring is a mildly radioactive cold mineral water; two bathing halls, Hohoemi-no-yu and Fureai-no-yu, hold 13 kinds of tubs including open-air baths, lie-down baths, waterfall massage, sauna and cold plunge. From the open-air bath you look out on the Mitsugi hills and, at night, a sky full of stars. Day bathing is ¥850 for adults and ¥500 for children with bath towel, face towel and loungewear included, and you may bathe as often as you like until you leave. Open 10:00–22:00 (last entry 21:30); the only closure is one or two days each June. Rest room, restaurant and massage room, with overnight stays available. About 8 minutes by car from Onomichi-kita IC, 25 minutes from Shin-Onomichi Station, or 50 minutes by Chūgoku bus from JR Onomichi Station to the terminus. A good soak after walking Onomichi's lanes or cycling the Shimanami Kaidō.
A town-run day spa on a 370 m hill in Ichikawamisato, south of the Kōfu basin. From the unobstructed open-air bath you take in the whole basin with Yatsugatake, Mt Kayagatake and the Southern Alps beyond, and after dark the carpet of city lights is certified as a 'Japan Night View Heritage' site. The water is a translucent tea-brown alkaline simple spring containing organic matter from ancient plants, smooth on the skin. Indoor bath, open-air bath, lie-down bath and sauna; adults ¥850, children ¥500; open late, 10:00–23:00 (last entry 22:30), so you can watch dusk turn to night from the tub. Closed only for maintenance days. The restaurant's hōtō noodles, chicken giblet stew and Kōshū wine-beef set, and the farm produce shop, are popular. About 10 minutes by car from Kōfu-minami IC or 7 minutes from JR Kai-Ueno Station. In summer you may even catch the Ichikawamisato fireworks from the open-air bath.
A large day spa where you can gaze at Nagasaki's night view — ranked among the 'new three great night views of the world' — from the bath. Built on the slope of Mt Inasa, its rooftop open-air bath looks down over Nagasaki harbour and the city, which turns into a sea of lights after sunset. The alkaline simple water fills carbonated, electric and jet baths; there are several saunas and cold plunges, six family baths with rest rooms, a suite of bedrock baths (extra charge) and a self-service canteen. Adults ¥850 on weekdays, ¥900 on weekends and holidays, children ¥450; family baths from ¥3,000 for 60 minutes. Open late, 09:30–01:00 (until 02:00 on Fridays, Saturdays and holiday eves; last entry 30 minutes before), with no fixed closing days apart from maintenance. A free shuttle bus runs from JR Nagasaki Station (about 20 minutes), a big plus without a car. The classic plan pairs it with the Inasayama ropeway: see the view from the summit, then soak. 320 parking spaces; payment is mainly cash.
An inn perched on a slope at Yunoyama Onsen in Komono, Mie, at the foot of Mt Gozaisho, proud of a bathing hall that looks across Ise Bay to the Chita Peninsula. Certified by the health ministry as a spa-based health-promotion facility, it admits day bathers without reservation — buy a ticket at the shop — for a modest ¥600 (children ¥300, infants ¥200). The water is Yunoyama's alkaline radium-bearing simple spring; from the indoor bath and panoramic open-air bath you get the Yokkaichi cityscape and sea at dusk and city lights at night. Riding the funicular-style incline elevator up the slope to the main building is part of the fun. Day bathing 11:00–20:00 (last entry 19:00); closing days are irregular, so check ahead. Restaurant and shop on site. About 5 minutes by shuttle (call ahead) from Kintetsu Yunoyama-Onsen Station or 5 minutes by car from Komono IC on the Shin-Meishin. Pairs well with the Gozaisho Ropeway — a soak after coming down the mountain.
A hot-spring complex on a rise in Haruno, Kōchi city, about 30 minutes by car from Kōchi Station, looking out over rice fields. Its big open-air bath fed by an abundant natural spring is the draw, with an indoor bath, a sand bath that warms you to the core, and in July–August a swimwear spa zone (pair baths, a children's spa and so on — ten in all), so families are many. Day bathing: adults ¥700, children ¥300, over-65s ¥500; open 10:00–21:00 (last entry 20:15), every day apart from occasional maintenance. The Haru Noie restaurant serves a weekly lunch, and a lodging wing with open-air-bath rooms starts at ¥8,650 with breakfast; being near the Haruno sports park it also hosts training camps. About 40 minutes by car from Kōchi Ryōma Airport, or 15 minutes on foot from the terminus of the Tosaden bus for JA Haruno; 60 parking spaces. A rare large open-air bath within Kōchi city, easy to fit between Katsurahama and the Niyodo Blue river.
The Umi no Kairō bathhouse of this large resort hotel on the Pacific shore of Kamogawa, on the outer coast of the Bōsō Peninsula, welcomes day visitors. Fed by Kamogawa Onsen, tapped in 2003, its open-air bath faces the ocean with an uninterrupted view of the horizon and breaking waves; there are also an indoor bath, sauna and a glass-walled lounge looking out to sea. Adults (junior-high age and up) pay ¥1,650 and children aged 3–12 ¥825, rising to ¥1,760/¥880 in peak periods such as Golden Week, summer and New Year. Towels are not included – rent a set for ¥330 or bring your own. Normal hours are 11:00–22:00 (last entry 21:00), but on weekends, holidays and busy days bathing is split into 11:00–15:30 and 19:30–22:00. Open every day, with entry limits when crowded, and day plans with spa treatments or lunch are available. About 5 minutes by shuttle or car from Awa-Kamogawa Station on the JR Sotobō Line, close to Kamogawa Sea World – a fine finish to a day at the beach.
A large hotel on a rise above Mikawa Bay in Gamagōri, part of Miya Onsen, whose waters are said to have been discovered 1,200 years ago by the monk Kūkai. Unusually for a coastal spa, the low-salt alkaline simple spring is known as 'beautiful-skin water'. Highlights are the open-air hot spring bath Bihakusen and 13 kinds of spa facilities across the men's and women's sides – lie-down baths, waterfall showers, saunas – with views over the bay toward Takeshima island. Day bathing runs 11:30–19:00 for ¥1,600 per adult (face towel ¥200 and bath towel ¥300 extra). Prices have risen, but the spacious halls and views are often yours alone in quiet hours; day plans with meals and private rest rooms are offered. Open every day, with free parking for 200 cars. About 5 minutes by car (20 on foot) from Mikawa-Miya Station on the JR Tōkaidō Line, or 20 minutes from the Otowa-Gamagōri IC on the Tōmei Expressway. Combine with Laguna Ten Bosch, Takeshima or mandarin picking on a Mikawa Bay drive.
A lone day-bath building among the fields on the outskirts of Nirasaki, north-west of the Kōfu basin, and a nationally known pilgrimage spot for onsen lovers. Nothing is added or altered – no dilution, heating, recirculation or chlorine – and as you settle into the tepid 38°C sodium chloride-bicarbonate spring, your whole body is coated in fine bubbles, said to be among the most abundant in Japan. The faintly greenish-yellow water carries a whisper of sulfur and iron, and the source running from a tap in the bathroom can be drunk (fizzy, iron-tinged). There is no open-air bath or sauna – just one big indoor pool and washing stations, like a sentō – but the windows frame the Yatsugatake and Kayagatake peaks, and the mild water makes an hour disappear. Adults pay ¥600, children ¥300, soap and shampoo provided. Open 10:00–20:00, closed Tuesdays (next day if a holiday) and Fridays, with free parking for 25 cars. About 10 minutes by taxi from Nirasaki Station on the JR Chūō Line or 15 minutes from Nirasaki IC on the Chūō Expressway.
Miyakojima is often assumed to have no hot springs, yet inside the Shigira Seven Miles Resort on the island's south coast lies one of Japan's southernmost and westernmost natural onsen. Golden sodium-chloride water rises undiluted from 1,250 m underground into separate men's and women's open-air baths and saunas wrapped in subtropical greenery, plus a swimsuit 'jungle pool' and lookout bath where families and couples can soak together – there are even floats for a full resort mood. Adults (12+) pay ¥2,000 and children 4–11 ¥1,000; guests of Shigira Resort hotels pay ¥1,600/¥800. Swimsuit rental is ¥510 and towels are rented for a fee. Open 11:00–22:00 (last entry 21:30), from 12:00 between mid-November and mid-March, every day, with a restaurant and relaxation salon on site. About 15 minutes by car from Miyako Airport, with resort shuttle buses in the evening. Combine it with Shigira Beach, south-coast sunsets and stargazing.
A day bath inside Alpa Komakusa, the Semboku city complex where buses depart for the 8th station of Mt. Akita-Komagatake. Sharing the building with the mountain information centre and volcano disaster station, it bustles with hikers and Lake Tazawa sightseers. The 'Nature Onsen Hall' has two lookout open-air baths, one of rock and one of hiba cypress, gazing down on the lapis-blue surface of Lake Tazawa – Japan's deepest – and the sweep of the mountains. The milky simple sulfur spring rises from the same range as Nyūtō and Mizusawa onsen and warms a chilled body thoroughly with a soft sulfur scent. Admission is a modest ¥550 for adults and ¥300 for children. Hours are 9:00–19:00 (last entry 18:00) from April to November, 9:30–17:30 (last entry 17:00) from December to March, and 9:00–18:00 on Thursdays and Fridays; open daily except Thursdays from November to April. Rest corner and light meals available, with a large car park. From JR Tazawako Station take the Ugo Kōtsū bus bound for Nyūtō Onsen about 35 minutes to the Alpa Komakusa stop. Perfect for a soak on the way to or from Nyūtō or after climbing Komagatake.
The lookout open-air bath of a long-established hotel crowning Shiroyama hill above Kagoshima city. Facing Sakurajima across Kinkō Bay, the outdoor bath is celebrated as one of Kagoshima's finest views, and after dark the city lights and the smoking volcano's silhouette are magical. The bicarbonate spring from 1,000 m underground is a skin-smoothing 'beauty bath', offered in indoor and outdoor pools plus the 'Ion Spa' hot spring sauna. Day bathing runs 13:00–21:00 and costs ¥3,500 for adults (tax and bathing tax included), ¥3,350 for junior-high students, ¥1,750 for elementary pupils and ¥800 for infants. It is pricey, but face and bath towels are included and you can use the hotel lounge, the Ippinkan gift shop and restaurants, making it a popular splurge for the view alone; reservable private baths start at ¥4,950 on weekdays for day guests. A free shuttle bus takes about 15 minutes from Kagoshima-Chūō Station, or 10 minutes by car from Tenmonkan. Pair it with the Shiroyama observatory and Saigō Takamori's historic sites and make a soak facing Sakurajima the highlight of your trip.
The largest and most storied inn of Ashinomaki Onsen, a spa strung along the Aga (Ōkawa) river gorge south of Aizu-Wakamatsu. Its soaring lobby 'floating stage', where live shamisen echoes each evening, became famous for resembling the bathhouse of a beloved animated film. The star is the 'superb-view open-air bath' cantilevered over the gorge, looking down on the river and the mountainsides through the seasons – spectacular in autumn colour and winter snow. The clear sodium-calcium sulfate-chloride water warms deeply and holds its heat. Day bathing runs 11:00–15:00 (reception until 14:00) for ¥1,800 per adult and ¥900 for ages 3–12, tax and bathing tax included with a face towel, open every day. The 'sky open-air bath' can be booked privately for ¥3,300 per 45 minutes (two slots each at 13:00 and 14:00), and day plans with lunch in a private room from ¥5,500 are popular. Free parking for 150 cars, pick-up from Ashinomaki-Onsen Station on the Aizu Railway, or about 40 minutes by car from Aizu-Wakamatsu IC via Route 118. A natural stop between Ōuchi-juku and the Tō-no-Hetsuri cliffs.
A city-run day spa (Niigata City Iwamuro Health Promotion Centre) at Iwamuro Onsen, a spa at the eastern foot of Mt. Yahiko in Niigata's Nishikan ward, often called 'Niigata's back parlour'. Set on a rise at the edge of the spa town, its main bath and open-air bath look out over the Echigo plain toward Mt. Kakuda and Mt. Yahiko. The indoor pool is heated tap water, but the small rock-lined outdoor tub is fed with rich, free-flowing sulfur-bearing sodium-calcium chloride spring (hypertonic, mildly alkaline) whose faint sulfur scent and floating mineral flakes feel unmistakably like real onsen. Admission is ¥650 for adults and ¥390 for children, and a face and bath towel set is included, so arrive empty-handed. Open 10:00–20:00 (last entry 19:30), closed the second and fourth Wednesdays (next day if a holiday) and 29 December to 3 January. An upstairs lounge allows re-entry, and there are rental rooms and a snack corner; free parking for 80 cars. About 10 minutes by car from Iwamuro Station on the JR Echigo Line or 20 minutes from Maki-Katahigashi IC. Pair it with Yahiko Shrine and Niigata's sake breweries.
A 400-year-old hot spring inn standing alone deep in the Ogawa river gorge that runs down from the Northern Alps in Asahi, the easternmost town of Toyama. Known as a fertility and therapeutic spa, it offers a circuit of five different baths. The great curiosity is the 'natural cave open-air bath', a dome of travertine built up over centuries from the spring's own mineral deposits and designated a prefectural natural monument – bathing inside it is an experience found nowhere else in Japan. There are also the streamside Renge-no-Yu outdoor bath, a rock bath and a cypress tub, all with free-flowing bicarbonate spring water that keeps you glowing long after. Day bathing runs 9:00–15:00 (reception until 14:30) for ¥1,000 per adult and ¥500 per child, or half price for the outdoor baths only. Irregular closures, and the two outdoor baths shut for winter from 1 December until the mid-April thaw. About 15 minutes by car from Tomari Station on the Ainokaze Toyama Railway, 30 minutes from Kurobe-Unazuki-Onsen Station on the Hokuriku Shinkansen (shuttle for overnight guests) or 15 minutes from Asahi IC. A hidden spring to pair with the Jade Coast and Unazuki on a drive along the Niigata border.
A stay-awhile day spa about 7 minutes on foot from JR Uno Station, right beside Uno Port where the ferries to Naoshima and Teshima depart. Jazz plays through the calm, old-farmhouse-style interior, and the great draw is the open-air bathing area gazing over the islands of the Seto Inland Sea and the boats passing between them. Outside are four baths around a large rock pool plus pot tubs; inside two pools, a sauna and cold plunge, with a rock-bed spa for an extra fee. The soft sodium-chloride spring rises from underground, and a soak in the sea breeze is the perfect cure for a day of art-island walking. Admission is on the high side – ¥1,700 for adults on weekdays and ¥2,000 on weekends and holidays (children ¥700/¥800) – but towels and loungewear are included, and a recliner lounge and restaurant serving Setouchi fish let you settle in for the day. Open 10:00–22:00 (last entry 21:00), closed the third Tuesday (the following Wednesday if a holiday), parking for 200 cars. A rare chance to bathe while waiting for the ferry back from Naoshima; about 40 minutes by car from central Okayama.
A popular day spa on a hillside of Mt. Tenpai in Chikushino, Fukuoka – the mountain where the exiled scholar Sugawara no Michizane is said to have pleaded his innocence to heaven. The main bath, Tenpai-no-Yu, uses natural spring water from 1,500 m underground and looks out over Chikushino to the distant lights of Fukuoka; the airy open-air bath is loveliest from dusk into night. Besides indoor and outdoor pools there are a sauna and cold plunge, and three styles of private family bath with their own open-air tubs (from ¥3,000 on weekdays, reservation required) make it a favourite with families and couples. Main-bath admission is ¥1,200 on weekdays and ¥1,300 on weekends and holidays for adults, ¥500/¥600 for ages 4 to elementary school (revised December 2024). Open 10:30–24:00 (last entry 23:00), closed as a rule on the second Tuesday. The buffet restaurant of Kyūshū produce is well regarded, with weekday lunch-plus-bath sets from ¥3,500. Parking for 200 cars, about 10 minutes by car from JR or Nishitetsu Futsukaichi Station or from Chikushino IC. The classic plan: visit Dazaifu Tenmangū, then climb the hill for a soak with the night view.
About 25 minutes by car from Morioka Station, this large hotel is the flagship of Tsunagi Onsen, the lakeside 'back parlour of Morioka' lined with inns along Lake Gosho. Its lake-facing bathhouse, the Nambu Magariya no Yu, is modelled on the region's traditional L-shaped farmhouses, and the open-air bath on the shore frames Lake Gosho and Mt. Iwate, beautiful as the light shifts at dawn and dusk. A second bathhouse, Hitorishizuka no Yu, looks onto a stone garden, and the two swap between men and women by time of day. The clear alkaline simple spring is soft on the skin, and there is a sauna. Day bathing hours are short – 11:00–16:00 on weekdays (reception until 15:00) and 11:00–14:00 on weekends and holidays (until 13:00) – at ¥1,200 on weekdays and ¥1,400 on weekends for adults, ¥600 for children. There is no fixed closing day, but cleaning days and crowds can suspend or shorten day bathing, so check ahead. A restaurant, shop and lounge are on site with ample free parking. Iwate Kenkō bus for Tsunagi Onsen from Morioka Station's west exit takes about 30 minutes, or 15 minutes by car from Morioka IC via Route 46. Combine with Koiwai Farm or Morioka Handi-Works Square.