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.
A large day facility where you can try Kusatsu's traditional 'awase-yu' — a row of wooden tubs at rising temperatures, entered in order. Indoor baths, rotenburo, sauna, plus rest and dining areas make it good for half a day. About 10 minutes' walk from the Yubatake, or a short bus ride. Admission ¥1,200 (2026); three-bath pass with Gozanoyu and Sainokawara ¥2,100.
Five minutes by shuttle from Hakone-Yumoto Station, a day-use-only bathhouse in the hills along the Sukumo River. Terraced rock rotenburo, a cave bath and a lukewarm pool invite long soaks. No reservation needed; rest rooms, restaurants and a reading lounge make it easy to stay half a day. Tattoos not permitted.
Two halves: the swimsuit spa zone 'Yunessun' and the traditional nude 'Mori no Yu'. Wine baths, coffee baths and water slides make it family-friendly and an easy first onsen for visitors. Tattoos allowed if covered with a sticker. Dynamic pricing in 2026: passport (both zones) from ¥3,500, swimsuit zone from ¥2,500, Mori no Yu only from ¥1,500.
An urban spa in front of Toshimaen Station, 20 minutes from Ikebukuro on the Seibu line. Natural hot-spring water drawn from 1,445 m feeds an open-air bath overlooking a Japanese garden, plus a swimsuit 'Bade' pool zone. Adults and teens only (junior high and up), so it stays quiet. Lounges, a restaurant and body care invite long weekday afternoons. No tattoos.
Right in front of the Yubatake, a wooden recreation of the Edo–Meiji communal baths. Wood and stone bath halls alternate between men and women daily, with two sources (Yubatake and Bandaiko). The upstairs hall looks down on the Yubatake.
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.
A storehouse-style communal bath halfway up the 365-step stone stairway. Iron-rich brown 'golden water' in indoor tubs; rest hall upstairs. Cashless payment accepted.
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.
Three minutes by free shuttle from Hakone-Yumoto. A farmhouse-style day spa whose 19 private open-air rooms are the draw (reserve ahead). The löyly sauna sessions in the main bath are popular too.
A free communal bath right beside the Yubatake that welcomes visitors. Shirahata source water flows into two wooden tubs (hot and hotter). No soap, no showers — this is the locals' bath, so keep it quiet and quick.
A large day-spa 12 minutes from Hakone-Yumoto Station, open 23 hours (10 am to 9 am). A 17-metre rooftop open-air bath, garden waterfalls and private baths. Overnight stays cost extra.
A day-spa on the hillside above Yumoto with five private spring sources feeding open-air, lie-down and jet baths. The ¥1,000 early-morning session (6–9 am) is among the cheapest soaks in Hakone.
The onsen hall of Kusatsu Onsen Hotel Village. Free-flowing source water in warm, hot and lie-down baths plus sauna for ¥930; add the swimsuit spa pool for families. The classic Kusatsu choice with kids.
The 1,300-year-old birthplace of Nasu Onsen. Inside the wooden bathhouse, tubs are graded from 41 to 48°C, all fed with milky, strongly acidic sulfur water. No showers, no soap — start with the traditional head-dousing ritual.
A day-use facility on the same source as Shika-no-yu, open every day until 9 pm with an open-air bath and private rooms. Ideal for families or anyone daunted by Shika-no-yu's rituals — the milky water is identical.
A public open-air bath built right at Ikaho's spring source, above the stone-step street and Kajika Bridge. Nothing but bamboo-fenced outdoor pools where the rusty-brown 'golden water' flows straight from the source. Pair it with the bridge in autumn.
Directly behind Hakone-Yumoto Station, a 3-minute climb up steps: a rustic wooden bathhouse with its own free-flowing spring and an open-air bath. Shōwa-era charm and surprising quiet for a station-front spot. Private indoor bath (¥1,000/45 min + entry) and a ¥200 footbath.
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.
A town-run day bath in the middle of the Minakami hot-spring street. Just one small indoor pool per gender, but 100% spring-fed sulfate water — an easy stop while strolling the town. Rest room, small shop and coin laundry give it the feel of a tourist office with a bath. 15 minutes on foot from Minakami Station. No soap provided.
A town-run day spa named after Yugawara's ancient name. Set on a rise above the Fujiki River near Manyo Park, with a large indoor bath, a mountain-view rotenburo, sauna, tatami lounge and restaurant. Admission drops to ¥600 after 19:00, so locals stroll the onsen street first and bathe in the evening. 12 minutes by bus from Yugawara Station to the 'Kogome-no-yu' stop.
Eight minutes from Shimura-sakaue Station in Itabashi, one of Tokyo's most atmospheric super-sento, built around a Showa-era mansion and dry-landscape garden. Free-flowing olive-green spring water in the rotenburo, high-concentration carbonated bath, stone sauna and a soba restaurant. ¥970 weekdays, ¥1,300 weekends and holidays; open until midnight. No tattoos.
A day spa perched on a bluff with the whole Pacific in front of it — both the rotenburo and the sauna face the sea, giving sunrises in the morning and fishing-boat lights at night. Carbonated bath, stone sauna and restaurant; open 9 am to 1 am. ¥950 on weekdays. About 10 minutes by car from Hitachi-Taga Station on the JR Joban Line, doable as a day trip from Tokyo.
In the hills of Tokigawa, Saitama, a popular day spa styled as a 1950s–60s Japanese town, complete with enamel signs and an old-fashioned sweet shop. Strongly alkaline (pH over 10) 'beauty' water that feels slippery on the skin, indoors and outdoors. Opens at 5 am on weekends for early bathers. ¥980 weekdays. About 1.5 hours from Ikebukuro by Tobu Tojo Line and town bus.
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.
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.
Kamata, 15 minutes by train from Haneda Airport, has Tokyo's densest cluster of 'kuroyu' black-water springs. Kaiseiyu, founded in 1929, is the classic: a coffee-dark natural bicarbonate bath, a high-concentration carbonated pool and a cold plunge, with a goldfish aquarium set into the bath wall. ¥600; a toiletries-and-towel set is sold at the desk. Ideal before a flight or after a late arrival. Tattoos are fine, as in most sento.
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.
About 80 minutes from Ikebukuro by Laview limited express, a complex hot-spring facility joined to Seibu-Chichibu Station. Themed on the 300-plus festivals Chichibu holds each year, it packs 9–10 tubs per side including open-air baths, a high-concentration carbonated bath and saunas. The food court serves waraji katsu-don and Chichibu soba; the shop sells local sake and miso pickles. ¥1,100 on weekdays, 10:00–22:00; morning baths from 6:00 on weekends.
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.
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.
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 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.
One of the Bōsō peninsula's largest spa resorts, in Shirako on Kujūkuri Beach. Soak in iodine-rich, tea-coloured Chōsei spring water in the open-air bath, with seven rock-bath rooms, saunas, nap lounges, banquet halls and lodging on site. Open straight through from 10:00 to 08:00 the next morning; stays past 01:00 incur a late surcharge. Free shuttle from JR Mobara Station (reservation required). ¥1,600 weekdays, ¥1,900 weekends. Tattoos—including stickers and paint—are strictly refused.
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.
A 12-room inn in Yoro Valley, the Boso Peninsula's autumn-colour spot and the last place in the Kanto region to turn, peaking late November to early December. Boso's signature coffee-coloured alkaline 'black water' fills the indoor and open-air baths; day use is a flat ¥700 for ages 3 and up, 11:00–15:00. Eat lunch in the dining room and the bath is free — spring bamboo-shoot dishes are the speciality. Five minutes by bus from Yoro-Keikoku Station on the Kominato Railway to Yorokan-mae. Lunchtime opening can be suspended at short notice, so phone ahead.
A super-sento 15 minutes by car from Kawagoe's 'Little Edo' warehouse streets, where brown natural spring water pumped from 1,200 m flows freely through both indoor and outdoor tubs. Nine baths per side plus two saunas, a carbonated bath and the signature 'Zabūn' water feature; the Zabūn and Sarasara wings swap between men and women on odd and even days. ¥900 weekdays, ¥1,000 weekends, ¥100 off 8–9 am and after 22:00. Open 8:00–25:00 every day with 200 parking spaces — a proper onsen near Tokyo to end a Kawagoe day.
A natural-spring super-sentō on the 5th–6th floors of the building linked by footbridge to the north exit of Kabe Station on the JR Ōme Line. The alkaline simple spring from 1,500 m down is known for leaving skin silky; the top floor has an open-air bath, lying bath, hot sauna and cold plunge plus an outdoor rest deck facing the Tama hills. Open 10:00–23:30 (last entry 23:00); ¥1,000 weekdays, ¥1,150 weekends, cheaper after 21:00. The Baijuan restaurant's weekday lunch-and-bath set is good value. The most convenient day onsen in western Tokyo — stop off on the way back to Shinjuku after hiking Mt Mitake, driving Okutama or browsing Ōme's retro shopping street. Closed the third Wednesday.
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.
A quiet bath-only annex within the Tenzan Tōjikyō grounds along the Sukumo River, up the valley from Hakone-Yumoto. Where neighbouring 'Higana Tōji Tenzan' is a full-day complex with lounges and dining, Ikkyū has no indoor bath at all — just open-air tubs of wood and stone fed free-flowing by two springs, a sodium-chloride and an alkaline simple spring. Silver-ion sterilisation (no chlorine smell), spare design and a hushed, no-chatter atmosphere keep regulars loyal. ¥1,200; open 11:00–20:00 (until 21:00 weekends and holidays, last entry one hour before), closed Thursdays. On weekdays a ¥300 'hashigo' ticket lets you add Tenzan next door. About 5 minutes from Hakone-Yumoto Station by the inns' shuttle bus or taxi, or a 25-minute walk.
Founded in 1691 and regarded as Japan's oldest surviving hot-spring inn building, this Shima Onsen institution in Gunma stands across a red bridge; the main house, said to be one of the models for the bathhouse in Spirited Away, is an Important Cultural Property. The celebrated Genroku-no-yu, built in 1930 in Taishō-romantic style, has five tubs set into a stone floor lit by arched windows, with water welling up from below. Shima's sulphate water is counted among Japan's three great baths for digestive ailments and can be drunk. Day use 10:00–17:30 (last entry 17:00), ¥1,500 with face towel, covering Genroku-no-yu, the mixed rock bath and private baths. Tattoos accepted if covered with stickers. About 40 minutes by bus from Nakanojō Station to the Shima Onsen terminus.
At 1,800 m in Manza Onsen — said to have the highest sulphur content in Japan — this is the most rustic of the old spa-cure inns. The wooden bathhouse holds just one indoor tub per gender, but the milky acidic sulphur water is thick and hot enough to leave you drowsy afterwards. It is known for its 'Sarunokoshikake-yu', in which extract of a bracket fungus has long been added to the water. Day use 10:00–16:00, ¥700 for adults, towels sold for ¥250. For onsen fans who want an old-school cure-bath feel amid Manza's big resort hotels. The building has tilted due to ground subsidence, so phone ahead to confirm it is operating. About 40 minutes by bus from Manza-Kazawaguchi Station.
A public-run hot-spring hotel on the clear Kuji River in Daigo, Ibaraki — the town of Fukuroda Falls. The main bath has an indoor tub and sauna, and from autumn to winter (Sep–Jan) it becomes the famous 'apple bath', floating with local apples. Day use 11:00–20:00 (last entry 19:30), ¥800 for adults including a face towel; open daily. A private barrel sauna (¥3,300 / 90 min, reservation), a post-bath lounge and a 16-hole ground-golf course in the garden are also available. About 10 minutes by taxi from Hitachi-Daigo Station and 15 minutes by car from Fukuroda Falls — easy to combine with the falls or apple picking.
Five minutes on foot from Musashi-Koyama Station on the Tōkyū Meguro line, this rare central-Tokyo bathhouse offers two different natural hot springs. The indoor bath is coffee-coloured 'kuroyu' (sodium-bicarbonate water); the open-air bath uses salty rust-brown 'golden water' pumped from 1,500 m below and left free-flowing — both certified as therapeutic springs. Admission is Tokyo's standard sentō rate of ¥550, with sauna and bedrock bath extra. Open 12:00–24:00, from 08:00 on Sundays; closed Mondays (open if a holiday). Close to Meguro and Gotanda, it pairs perfectly with snacking along the Palm shopping arcade. Soap and shampoo provided.
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.
A city-run day spa in the Kiyotaki valley, between Nikkō's World Heritage shrines and the Irohazaka switchbacks. The all-granite main bath has a sauna and jacuzzi, and the garden-style rock rotenburo looks out to the Nikkō mountains. The alkaline simple spring is clear and silky — a 'beauty bath'. Open 10:00–21:00 (last entry 20:30), closed Thursdays (next day if a holiday) and over New Year. Adults from outside the city pay ¥1,000 (¥500 for residents). The canteen serves soba, udon and other light meals. About 20 minutes by bus from JR/Tōbu Nikkō Station to the 'Yashio-no-yu' stop — a popular finish after Tōshōgū or a trip to Lake Chūzenji and Kegon Falls.
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.
One of the largest spa complexes in Saitama, in Kumagaya in the north of the prefecture. Its own alkaline simple spring, pumped from 1,500 m at over 600 litres a minute, feeds a wide range of tubs — a free-flowing open-air 'raw source' bath, pot baths, lie-down baths and a high-concentration carbonated bath. There is a löyly sauna, cold plunge and a garden-view outdoor rest deck. The optional 'Onkatsu Café Nest' adds eight kinds of bedrock-bath rooms, manga and free drinks for an all-day stay. Admission ¥950 on weekdays, ¥1,100 on weekends and holidays; open 10:00–23:00 (last entry 22:30), no closing days. Private rooms with an open-air pot bath can be reserved by phone. About 10 minutes by bus or taxi from JR Kumagaya Station; 300 free parking spaces. Kumagaya is about 40 minutes from central Tokyo by Shinkansen — combine with rugby at the stadium or Menuma Shōdenzan temple.
A natural hot spring to visit after strolling Kawagoe's 'Little Edo' warehouse street. Its own sodium-chloride spring from 1,200 m fills indoor and open-air baths in two zones, 'Wood' and 'Stone', which swap between men and women daily. Nine baths and three saunas in all — a carbonated bath made by dissolving CO₂ into the spring water, a free-flowing source bath, bedrock-bath rooms and a private family bath — make for an in-house bath-hopping course. Adults ¥850 on weekdays, ¥950 on weekends and holidays; open 10:00–24:00 (from 09:00 on weekends and holidays, last entry 23:00), no regular closing day apart from maintenance. Body soap and shampoo provided; a soba-and-udon restaurant, massage and body scrub are on site. Seibu bus from Hon-Kawagoe Station (Seibu Shinjuku Line) to the 'Hōmukyoku' stop; 150 free parking spaces.
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.
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 hideaway day spa in a copse of trees near Jindaiji, Tokyo's second-oldest temple, and its soba-shop village. The blackish-brown 'kuroyu' sodium-chloride water from 1,500 m carries compounds from ancient plant matter, feels viscous on the skin and keeps you warm long after. The wooden bathhouse holds an indoor bath, a rock open-air bath, sauna and cold plunge, and an outdoor rest deck among seasonal greenery — more like a country inn than a big spa complex. Adults ¥1,080 on weekdays, ¥1,180 on weekends and holidays, with cheaper 30-minute and one-hour tickets. Open 10:00–22:00 (last entry 21:00), every day apart from inspection closures. A soba restaurant and rest room are on site — a fine finish to Jindaiji temple and the Jindai Botanical Garden. Free shuttle buses from Chōfu and Tsutsujigaoka stations.
A town-run day spa on a rise above the Kuji River in Daigo, Ibaraki, the town of Fukuroda Falls, one of Japan's three great waterfalls. The alkaline simple water is soft; there is a large indoor bath with a waterfall-massage and bubble bath, and the pride of the place is an open, airy outdoor bath with a sweeping view of the Yamizo hills and the river — especially fine in autumn colour. Sauna, rest room, Japanese restaurant and shop, used equally by locals and visitors. Adults ¥710 on weekdays, ¥1,010 on weekends and holidays (¥500 after 17:00), children ¥350/¥500; open 10:00–20:00 (last entry 19:30), closed the 1st and 3rd Wednesdays and December 31. Soap and shampoo provided, towels sold. About 15 minutes by bus from JR Hitachi-Daigo Station to 'Mori-no-Ideyu'; about an hour by car from Naka IC. Combine with Fukuroda Falls and the local shamo chicken cuisine.
A natural-spring bath complex about 5 minutes on foot from Minami-Tama Station (JR Nambu Line) in Inagi, amid the greenery of the Tama hills. The mildly alkaline water from 1,700 m down is pale amber and soft on the skin; the outdoor area has a free-flowing rock bath, pot baths, lie-down baths, a carbonated bath and seasonal specials, while indoors are a high-concentration carbonated bath, jet baths, a sauna with löyly sessions and a cold plunge. With more room than central-Tokyo spas, its outdoor rest deck among trees is a real draw. Entry: adults ¥1,000 on weekdays, ¥1,200 on weekends and holidays; children ¥520/¥680; bedrock baths extra (¥750 on weekdays). Open 09:00–01:00 on weekdays and 07:00–01:00 on weekends and holidays (last entry midnight). Closed only on the third Tuesday of March, June, September and December. Restaurant, body care and a manga corner on site. About 40 minutes from Shinjuku via the Keiō and Nambu lines, easy to pair with Yomiuriland or a walk in the Tama hills.
A natural-spring bath complex on a wooded Musashino plot in Saitama's Nishi ward. The source, over 600 litres a minute from 1,500 m down, is a faintly green-tinged amber sodium-chloride water; in the outdoor area the rock bath and 'source tepid bath' are filled free-flowing without heating or dilution, and the place is famous among enthusiasts for its 'nuru-yu culture' of long soaks at around 38 °C. There are also raw-source pot baths, lie-down baths, a high-concentration carbonated bath, a sauna with löyly and a deep cold plunge, and an outdoor rest area facing the trees — remarkably quiet for the suburbs. Adults ¥880 on weekdays, ¥980 on weekends and holidays; children ¥500/¥550; open 10:00–24:00 (last entry 23:30), irregular closures. Restaurant, body care and scrub treatments on site. About 25 minutes by bus from JR Ōmiya Station to 'Seiganji', or by taxi from Ageo or Sashiōgi stations. A must for tepid-bath lovers in the Tokyo area; large car park.
A municipal day spa in the Suifu district of Hitachiōta, Ibaraki, near the Ryūjin Great Suspension Bridge, famous for Honshū's highest bungee jump at 100 m. It fills with visitors combining it with the gorge's autumn colours or carp-streamer festival, plus locals. There are two bathrooms — one with an open-air bath, one with a sauna — swapped daily between men and women, so check ahead if you want the open-air side. The clear, soft simple spring is known for warming you well. Adults ¥800 on weekdays, ¥1,000 on weekends and holidays; children ¥400/¥500; cheaper after 16:00. Open 10:00–20:00 (last entry 19:00), closed Tuesdays and Wednesdays (the next business day if a holiday) and December 29–January 3. Restaurant (the mapo tofu is popular), rest room and 70 parking spaces. About 50 minutes by car from Naka IC, or by city bus from JR Hitachi-Ōta Station to 'Keganorokku' then 4 minutes on foot. A handy waypoint on a northern-Ibaraki drive with Fukuroda Falls and Oku-Kuji.
A day-use hot spring in Sekiya, Nasushiobara, near the Yunoka Shiobara roadside station at the gateway to the Shiobara spa valley. The source flows at 68.4°C and 250 litres a minute, so the open-air bath runs 100% free-flowing spring water. The slightly tea-coloured, silky alkaline simple spring is known as a skin-beautifying bath; the indoor pool seats about 20 and the outdoor one about 10, both roomy. There are a sauna, cold plunge, jet lounger and a swimwear spa pool popular with families. Adults pay ¥800 on weekdays and ¥1,000 on weekends and holidays (children 4 to elementary age ¥400/¥500); after 5 pm on weekdays the evening rate drops to ¥600. Open 10:00–22:00 (last entry 21:00), closed the third Wednesday (next day if a holiday). Restaurant, rest room, massage and free parking for 150 cars. About 20 minutes by car from JR Nishi-Nasuno Station or 10 minutes from the Nishinasuno-Shiobara IC on the Tōhoku Expressway – a handy last stop after a drive through the Shiobara gorge or Nasu.
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.
An urban natural hot spring 8 minutes on foot from JR Sugamo Station, named after Somei village, birthplace of the Somei-Yoshino cherry. Renovated in August 2025, the interior is now calmer and more Japanese-modern. Amber sodium-chloride strong-salt water pumped from 1,800 m underground holds heat so well it is called the 'bath of warmth', enjoyed in an outdoor rock bath, pot tubs and a garden-view indoor pool, with a hot sauna, cold plunge, outdoor cooling area and a mist sauna on the women's side. Admission including towels and loungewear is ¥2,100 on weekdays and ¥2,900 on weekends and holidays for adults, ¥1,200 for children aged 6 to elementary school – city prices, but with no time limit you can stay all day. Open 10:00–23:00 (last entry 22:30), irregular maintenance closures. Japanese, Western and Chinese dining, a large tatami rest hall, body care, scrubs, esthetics and even hair styling are on site, and a free shuttle bus runs from Sugamo Station; parking for 88 cars (2 hours free on weekdays). Combine it with Sugamo's Jizō-dōri shopping street or Rikugien garden for the closest thing to an onsen getaway on the Yamanote Line.