Super sento, spas and bathhouses in Tokyo, Osaka and Kyoto.
Day-use onsen need no reservation: pay at the desk and walk in. That makes them ideal for loosely planned trips or days when you want to follow the weather.
This list gathers day facilities you can drop into without staying overnight. Ryokan often open to day bathers only for a short window (say 14:00–18:00), so do check hours and closing days. Some limit entry when crowded.
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.
A giant bath complex next to Tsutenkaku Tower in Shinsekai. The 'Europe zone' (Rome, Greece, Mediterranean) and 'Asia zone' (Bali, Persia) swap between men and women each month. There's also a swimsuit pool, stone saunas and hotel floors. Open 24 hours, so it doubles as a place to stay after the last train. Tattoos OK if covered with a sticker.
Founded in 1923, a registered cultural-property bathhouse with a curved-gable entrance, carved transoms in the changing room and majolica tiles. Despite the 'onsen' in its name the water is heated, with electric bath, herbal bath, open-air pool and sauna. One of Kyoto's few tattoo-friendly baths, so popular with visitors. ¥550; opens 8 am on Sundays.
A day-use hot spring in Fukui city's Koshino district on the Echizen coast, famous for its wild daffodil fields. The mildly alkaline water is soft on the skin, and there is an indoor bath facing the Sea of Japan, a sauna and a small open-air tub. Adults pay just ¥640 and shampoo/body soap are provided. Open 10:30–20:30 on weekdays and 09:30–21:30 on weekends; closed 1st/3rd/5th Tuesdays (next day if a holiday). Winter (Dec–Feb) brings the daffodils and Echizen crab season, and many visitors stop here to finish a coastal drive. About 40 minutes by car from central Fukui; buses are infrequent, so a car is realistic.
The flagship bathhouse of Nagayu Onsen in Ōita, which bills itself as Japan's best carbonated spring. Its European look comes from a sister-city tie with Bad Krozingen in Germany, and inside the water flows straight from the source with no heating or dilution. The rust-brown sodium-bicarbonate water is rich in iron and CO₂, and fine bubbles cling to your skin in the tub. Gender-separated indoor and open-air baths on the 1st and 3rd floors swap daily. Open 06:00–21:00 (last entry 20:00) — great for an early soak; closed the 3rd Wednesday of each month. Adults from outside the city pay ¥700; a private family bath is ¥2,400 for 50 minutes. Cards and QR payment accepted. 25 minutes by car from JR Bungo-Taketa Station.
Three minutes on foot from Gozen-yu, this is the gender-separated communal bath locals use every day. You pay ¥300 at a ticket machine and walk in — no attendant, and the bathroom holds just one indoor tub. Nagayu's bicarbonate water flows freely and has stained the spout area brown with mineral deposits. Open 06:00–22:00 (last entry 21:30), closed the 4th Wednesday. No soap or shampoo, so bring your own. If you are walking around Nagayu, add this ¥300 locals' bath to Gozen-yu and the free riverside Gani-yu.
A public bathhouse (doubling as a self-catering lodge) in the centre of Dake Onsen, about 600 m up the slopes of Mt Adatara. The acidic spring is rare nationally; piped roughly 8 km from the source, the water cools on the way and arrives milky white with a slight tingle. The basement bath is indoor only but 100% free-flowing. Day use 10:00–19:00 (last entry), ¥400 for adults, closed Tuesdays. The sloping resort street keeps traces of the town's playful 'Nikoniko Republic' era and has a free foot bath. About 25 minutes by bus from Nihonmatsu Station; popular with hikers coming down Mt Adatara and skiers.
The oldest communal bath in Echigo-Yuzawa, near the inn where Kawabata Yasunari wrote Snow Country — he is said to have bathed here himself. The tub fits only five or six people, but the sulphur-scented free-flowing spring is a rarity in Yuzawa and the star of the town's five-bath 'sotoyu' circuit. Adults pay ¥850 including bathing tax (revised 2026); open 10:00–21:00 (last entry 20:30), closed Tuesdays. Soap and shampoo provided, towels sold for ¥200. It sits up a slope 25 minutes' walk from Echigo-Yuzawa Station, or 10 minutes from Gala-Yuzawa Station; only 10 parking spaces.
The municipal day-use bathhouse of Nibukawa Onsen — one of the 'three baths of Iyo' alongside Dōgo and Hontani, with a history back to the Edo period. Built beside the clear stream of Nibukawa Gorge, it has indoor and open-air baths and a sauna overlooking the valley. The mildly alkaline, radon-bearing simple spring is a silky 'beauty bath'. Adults pay just ¥420, and there is a rest hall, a snack corner and a shop with local produce. Open 10:30–21:00 (last entry 20:30); closed 2nd and 4th Mondays (next day if a holiday) and over New Year. About 30 minutes by bus from Imabari Station to 'Seseragi Kōryūkan-mae'. Popular with cyclists finishing the Shimanami Kaidō.
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.
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 day-use hot spring in the Jūnibō forest of Kōnan, Shiga, near Ishibe, an old post town on the Tōkaidō. The two bathing areas, Shugen-no-yu and Momotsute-no-yu, alternate between men and women daily, each with an indoor bath, dry sauna and free-flowing open-air bath; the high-pH alkaline water feels slippery on the skin. Adults pay ¥800, and the complex also has a restaurant, gym, massage, pottery and craft workshops, an indoor onsen pool (late Apr–mid-Oct, extra) and a reservation-only campground. Open 10:00–22:00 (last entry 21:20); closed only over New Year and for maintenance. About 10 minutes by car from Kōsei Station on the JR Kusatsu line and close to Ritto-Kōnan IC — pairs well with the autumn-leaf temples of the 'Kōnan Sanzan'.
Tawarayama Onsen, in the hills of Nagato, Yamaguchi, has 1,100 years of history and still lives by 'sotoyu' culture: the inns have no baths of their own, so even overnight guests walk in yukata to the two communal bathhouses, Machi-no-yu and Hakuen-no-yu. Hakuen-no-yu is the newer of the pair, with three tubs — a lukewarm No.1 bath straight from the source, a heated hotter No.2 bath and an open-air bath — showcasing silky pH 9.9 alkaline water. ¥850 for adults, open 12:00–21:00, closed Tuesday to Thursday (Machi-no-yu runs daily 06:00–22:00 for ¥650). A free foot bath sits halfway up the entrance stairs. About 20 minutes by bus from Nagato-Yumoto Station.
The communal bath of Maga Onsen, a tiny hamlet of stone stairways on a slope above a tributary of the Asahi River in the Yubara Onsen area. Legend says a defeated warrior healed his wounds here some 700 years ago. The star is the 'Makuyu', a mixed rock bath of about 1.6 × 2 m and 1.2 m deep, so you soak standing up — often called Japan's smallest mixed bath — with lukewarm 39°C water bubbling up through cracks in the rock floor. The men's and women's baths connect to it and cost ¥250; the Makuyu is ¥400 (max 8 people, one hour) and a private bath ¥1,300 for up to three. Open 08:00–21:00 (last entry 20:10), closed Tuesdays (open on holidays). No towels allowed in the mixed bath, so be prepared. About 20 minutes by car from Chūgoku-Katsuyama Station.
Halfway along Ideyu-zaka, the steam-wreathed main street of Beppu's Kannawa district, this communal bath is run by the local residents' association. In typical Beppu style the changing area and bath share one room, and hot sodium-chloride water rich in metasilicic acid flows freely. Visitors pay only ¥100 — technically a coin-locker fee rather than admission. Open 06:30–21:00 daily. No soap or shampoo and minimal washing space, so follow local manners: quiet and quick. There is a toilet on the little square out front, and the Jigoku-mushi steam-cooking workshop and Umi-jigoku are two minutes away, making it an easy stop on a Kannawa stroll. Counts toward the Beppu Hattō Onsen-dō stamp rally.
A hidden spring on the site of an old copper mine in the hills of Kumano, Mie. The abundant water is entirely free-flowing with no dilution or heating; the clear sodium-chloride spring warms you to the core. The cedar-scented bathhouse, rebuilt in 2015, has an indoor bath, an open-air area with standing, half-body and lying baths, and a private bath for ¥1,080 per hour. Admission ¥600 for adults, open 09:00–21:00 (last entry 20:15), irregular closures. A trolley train through the old mine tunnel (about 10 minutes) links it with Iruka Onsen Seiryūsō and is a famous ride in itself — but as of 2026 it is suspended for safety inspections, so check ahead. Half-price admission on the 26th of each month. About 40 minutes by car from Kumano-Ōdomari IC.
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.
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'.
In the town centre of Ibusuki, famous for its sand baths, this is one of the oldest communal baths, dating from 1882. Locals call it 'Muran-yu'. Its pride is the wooden bathhouse and the spring that wells up straight through the floor of the tub; there are no taps — you scoop the emerging water with a bucket to rinse, the old way — and there are two tubs, hot and lukewarm. The sodium-chloride water is strongly salty in true Ibusuki fashion and keeps you warm for ages. Adults drop ¥350 into the unattended fee box; open 08:00–22:00. No soap provided, so bring your own. About 13 minutes on foot from Ibusuki Station. For onsen fans who want a 'real locals' bath' after the Saraku sand-bath hall; entry may not be possible during cleaning or crowding, so check closure days in advance.
Hijiori Onsen, 1,200 years old, is a cure-spa where inns huddle at the bottom of a caldera in Ōkura village, Yamagata. Right in the middle of the street stands Kami-no-yu, the only communal bath open to visitors. A small bathhouse with an attendant's counter, it has slightly hot free-flowing sodium-chloride/bicarbonate water and a tiny Yakushi shrine in the corner of the tub. Adults pay ¥400 (free for guests of the village inns); open 08:00–18:00 (until 17:00 in winter), no bathing on Thursday mornings for cleaning. The Hijiori way is to pair it with the morning market that sets up from about 5–6 am (Apr–Nov). In winter this is one of Japan's snowiest places, and just walking the street between snow walls is an experience. About 55 minutes by bus from Shinjō Station.
The communal bath at the heart of Nuruyu Onsen in Kuroishi, Aomori, a spa with more than 400 years of history. It is ringed by 'kyakusha' — simple self-catering cure lodgings with no baths of their own, whose guests all walk over here — a form of spa life now rare even in Tōhoku. The bathroom is as roomy as a sentō, with 100% source water (sodium chloride-sulphate) cooled by a special method without dilution and split into hot and lukewarm tubs. Adults pay ¥350; open long hours from 05:00 to 22:00 (last entry 21:30), daily (occasional closures in April and November). No soap provided. Kokeshi-doll workshops and the Tsugaru Kokeshi Museum are nearby. About 25 minutes by bus from Kuroishi Station.
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.
Tsuetate Onsen, where inns line both banks of the Tsuetate River on the Kumamoto–Ōita border, claims 1,800 years of history as the bath water of the infant Emperor Ōjin. Moto-yu is the communal bath said to be its origin: a single half-open tub carved into the rock face beside the riverside promenade — mixed, free and open 24 hours, nothing more. The sodium-chloride water, cooled from a 98°C source, leaves the skin soft. Changing space is basic and screening minimal, so many people wear bathing garments or a wrapped towel; early morning or night is the best time. Combine it with a wander through the 'sedoya' back alleys and, in May–June, the 3,500 carp streamers strung across the river. About 50 minutes by bus from Hita Station.
Yunohama Onsen is a seaside spa on the Sea of Japan in Yamagata's Shōnai region. This municipal communal bath sits on the ground floor of the 'Cospa' community centre on the roundabout at the centre of the resort and is the locals' everyday bath. It uses a blend of Yunohama's springs — sodium-calcium chloride water — free-flowing with only a little dilution, in a single no-frills indoor tub. Adults pay ¥400; open in two sessions, 06:00–07:00 and 10:00–21:30, closed 2nd and 4th Thursdays. Soap and shampoo sold for ¥200, towels ¥100. The beach is two or three minutes' walk away, and the best plan is to watch the famous Yunohama sunset before soaking. About 35 minutes by bus from Tsuruoka Station.
A Western-style bathhouse on the shore of Lake Suwa, built in 1928 by the Katakura silk dynasty for the welfare of local residents and now an Important Cultural Property. Its famous Sennin-buro is a marble pool 1.1 m deep — you bathe standing, pebbles underfoot, surrounded by stained glass and sculpture — named for the hundred people it can hold at once. It uses Kamisuwa's spring water and also has a sauna and jet bath. Adults ¥750, open 10:00–20:00 (last entry 19:30), closed 2nd and 4th Tuesdays. The 2nd-floor rest room (until 19:00) and canteen (11:00–15:00) are open to bathers, and tours of the hall building are offered. Eight minutes on foot from Kami-Suwa Station, handy for Suwa Taisha shrine and Takashima Castle.
Hakodate's signature day-use hot spring at the foot of Mt Hakodate, five minutes on foot from the Yachigashira tram terminus. Opened by the city in 1953 and privatised in 2013, when a sauna was added. The high-ceilinged bathroom feels airy; the rust-brown sodium-chloride water is strong and on the hot side, and the open-air bath is star-shaped after Goryōkaku fort. Adults pay just ¥490; open 06:00–22:00 (last entry 21:00), closed 2nd Tuesdays. A 'hands-free set' with towels is sold and there is a canteen. Close to the Mt Hakodate ropeway, Cape Tachimachi and the morning market — bathe with the locals at dawn or to round off a day of sightseeing. Soap and shampoo provided.
Amagase Onsen, where steam rises along the Kusu River in Hita, Ōita, is counted with Beppu and Yufuin among the 'three great springs of Bungo'. Its trademark is the communal open-air baths dotted along the riverbed, and Yakushi-yu is one of the most approachable: a single rock tub, mixed bathing, ¥100 dropped into an unattended box. The 75°C simple sulphur spring is diluted to a comfortable temperature, with a faint whiff of sulphur and a view of the spa street across the river. Open 10:00–22:00 daily; wrapping a bath towel is allowed, which makes it easy for first-timers, and it is lit and atmospheric at night. Stroll the town, rebuilt after the 2020 floods, and try the other riverside baths such as Kanda-yu and Ekimae Onsen. About 10 minutes on foot from JR Amagase Station.
The public bathhouse at the heart of Yamashiro Onsen's 'Yu-no-gawa' square in the Kaga hot-spring region, a spa 1,300 years old. In Kaga communal baths are called 'sōyu', and even ryokan guests walk over in yukata. The entrance reuses the gate of the old Yoshinoya inn; inside is spacious and clean, with one big tub of fresh undiluted water (sodium-calcium sulphate-chloride) flowing freely. Adults ¥500, open 06:00–22:00, closed only on the morning of the 4th Wednesday. A ¥900 combined ticket includes the 'Ko-sōyu' opposite (¥700), a recreation of the Meiji-era bathhouse with Kutani-ware tiles and stained glass — comparing the two is the classic plan. Soap and shampoo are sold, not provided. About 10 minutes by bus from Kaga-Onsen Station.
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.
The oldest of Itō Onsen's 'Seven Lucky Gods' communal baths, a true locals' bathhouse. The spring is said to have been presented to the third shōgun Tokugawa Iemitsu in the Edo period, and today it runs as the ward-operated Wada-yu Kaikan. The layout is simple — a single indoor bath each for men and women — but the clear, simple-type spring flows in freely and the atmosphere is that of an old-fashioned neighbourhood bath full of regulars. Adults ¥400, children ¥200; open 14:00–22:00, closed Wednesdays (with extra days off in even months — check ahead). Soap and towels are sold, so bring your own. About 15 minutes on foot from JR Itō Station; pair it with the Tōkaikan building and Kinema-dōri street as one stop on the Seven Lucky Gods bath circuit. Parking for 11 cars.
A day-use bathhouse on the main street of Hirayama Onsen, where inns are scattered among the rice fields of Yamaga, Kumamoto. The slippery alkaline simple-sulphur water — famed locally as 'beautifying water' — fills a main indoor pool, electric bath, waterfall massage bath, cold plunge and sauna plus two open-air baths of different sizes. Adults ¥600, children ¥300 (a bath-only course is cheaper still); open 09:30–21:30 (last entry 20:30), closed Thursdays (open if a holiday). Paid private rest rooms (10:00–16:00), a farm-produce and souvenir shop and a café round it out, and the crowd is half locals, half visitors. Kyūshū Sankō bus from Yamaga Bus Center to 'Hiraogi', then 7 minutes on foot; about 20 minutes by car from Kikusui or Nankan IC. Pair with Yamaga's lantern festival heritage and the Yachiyoza theatre.
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 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 big bathhouse in Kanie, just west of Nagoya, open since the 1960s and known among Tōkai-region onsen fans as 'the real thing'. Two of its own springs, one cool and one hot, are blended to bathing temperature and run untouched — no dilution, no recirculation — into both indoor and outdoor baths. The showpiece is a garden-style indoor hall of a scale you would not expect, with pools of various sizes among rocks and greenery. The clear simple spring is soft and leaves you refreshed. Adults ¥700 on weekdays, ¥800 on weekends and holidays; open 13:00–23:00 (last entry 22:30), no closing day apart from occasional maintenance. Soap and shampoo provided; a tatami hall and restaurant on site. About 7 minutes by taxi from Kintetsu Kanie Station or 17 minutes on foot from JR Eiwa Station; 250 free parking spaces. A rare chance at free-flowing source water within 30 minutes of Nagoya Station.
Tottori Onsen is a national rarity — a hot spring rising right in front of a prefectural-capital station — and this Shōwa-retro bathhouse at its heart is about five minutes' walk from JR Tottori Station. Old-style layout with a bandai counter and just one pool split into deep and shallow halves, but the 46°C-plus sodium-sulphate-chloride water is properly hot and leaves skin silky. Adults ¥550, children ¥200; open in two sessions, 06:00–10:00 and 14:00–24:00, closed the 2nd Monday and New Year's Day. No soap provided — bring or buy. Good after walking the Tottori sand dunes or castle ruins, or as a morning bath before an early train. Parking for 11 cars plus coin car parks nearby.
The founding bath of Yunotsu, the port town that once shipped silver from the World Heritage Iwami Ginzan mine, with a history said to go back 1,300 years. It stands in the preserved townscape district and has a legend of a tanuki healing its wounds here. Two pools: the 'hot' one fed directly by the source and a 'cooler' one that is still around 43°C. The strong sodium-calcium-chloride water, thick with rust-brown mineral flakes, is renowned as a therapeutic spring and can be drunk. Adults ¥450, children ¥200; open 06:00–20:00, irregular closures (closed from 15:00 on the 3rd Monday). No soap and no showers — bathe the old way. Comparing it with the other outside bath, Yakushi-yu (¥500), is the classic routine. About 20 minutes on foot or 5 by bus from JR Yunotsu Station.
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 municipal day-use bathhouse in the Furuyu–Kumanokawa spa area along the Kase River, about 30 minutes by car from central Saga. Kumanokawa's water is a radon-bearing radioactive (radium) spring, traditionally enjoyed as a long, slow soak at lukewarm temperature. The main hall has large and small pools at different temperatures, an open-air bath facing the hills, and a small sauna and cold plunge, all lively with local chatter. A barrier-free family bath (¥1,500 for 55 minutes plus admission) is available, and the tatami rest room offers meals and massage. Adults ¥600, children ¥350; open 10:00–21:00, closed the 3rd Thursday (next day if a holiday). Local vegetables are sold at the front desk, and the grounds have a hot-water stand and a 'Yu YOU Park' for car camping. Pair with Furuyu Onsen for a bath-hopping day.
A day spa (formerly Aoidake-sō) rebuilt as the centrepiece of Aoidake Nature Park in the Sakai River valley between Miyazaki and Miyakonojō. The alkaline simple spring, once picked among Japan's 'top ten viscous waters', has a silky feel; besides the main bath there are a walking bath, an electric bath, an open-air bath facing the green gorge and a sauna. The optional thermal lounge 'Yurukotto' adds bedrock-bath rooms and recliners for a long stay. Adults ¥700 on weekdays, ¥900 on weekends and holidays (¥1,000 on special days; discounts 07:00–10:00 and after 19:00); baths open 07:00–21:30, every day apart from inspection closures. An RV park, campsite and river-play spots sit alongside, ideal for a family outdoor day. 15 minutes on foot from JR Aoidake Station (pick-up available); about 15 minutes by car from Tano IC.
Because drilling is banned inside the national park, every bath in Unzen runs on naturally rising water. This little communal bath on the edge of the spa town, known locally as 'Dankyū-buro', has just one deep oval pool into which the acidic hydrogen-sulphide spring flows fresh; depending on the season and the day it may be milky white or nearly clear. It is hot, 43–44°C, with a faint sulphur scent. Adults ¥200, children ¥100; open 09:00–22:00, closed Tuesdays. No dryers or amenities — soap is sold — but there are lockers, and parking for four cars. After touring the Unzen Hells, a rare chance to taste the local bath for ¥200, a world apart from the big tourist bathhouses.
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 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.
A town-run day spa inside the hilly 'Toyama Forest of Health – Green Park Yoshimine', about 15 minutes by car from Tateyama Station, the Toyama gateway to the Tateyama-Kurobe Alpine Route. The clear, mildly alkaline simple spring is piped straight from the source and called 'beauty water'; besides the main bath there is a rustic rock open-air bath, an herbal bath and a sauna. From April 2026 adults pay ¥750 and children ¥380; open 10:00–21:00 (last entry 20:30), closed Tuesdays (plus maintenance days). The park has a campsite, barbecue area, park golf and the Yoshimine Heights lodge, making it a handy stop before or after the Alpine Route or a Tateyama climb. About 5 minutes by car from Iwakuraji Station (Toyama Chihō Railway), 20 minutes from Tateyama IC; 300 parking spaces.
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 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 city-run hot-spring and sports complex at Yuya Onsen, the noted spa of Oku-Mikawa strung along the Ure (Itashiki) River gorge in Shinshiro, Aichi. Rare in being reachable by rail — about 10 minutes on foot from Yuya-Onsen Station on the Iida Line — it has a large bathing hall with a main tub, bubble bath, jet bath and lie-down bath, plus an open-air bath within earshot of the river and its greenery. The sodium-calcium-chloride water warms you thoroughly. Bathing only: adults ¥620, children ¥310; the heated pool (with water slide) and gym are extra, or an all-facility ticket is ¥1,150. Open 10:00–21:00 (last entry 20:15), closed Tuesdays (the day before if a holiday), December 29–January 1, and for maintenance in March and October. The restaurant serves gohei-mochi and set meals. Combine with a hike up Mt Hōraiji, Hōrai Gorge or the Atera Seven Falls. About 20 minutes by car from Shinshiro IC on the Shin-Tōmei.
The communal bathhouse of Shikano, a castle town in western Tottori City laid out by the warlord Kamei Korenori. Light pours through glass-block walls into a bright bathroom with a main tub, jacuzzi, sauna, cold plunge and an open-air bath facing Mt Jūbō, all generously filled with clear, gentle simple spring water. Inexpensive at ¥550 for adults and ¥280 for children; open 10:00–22:00 and closed only on the first Thursday of the month (the following week if a holiday). There is no restaurant, but a rest area and souvenir counter, plus a roofed foot bath and the 'Omoshiro Market' soba house next door. Pair it with a stroll around the castle town's canals and paving, Shikano Castle ruins park and the Bird Theatre. About 4 minutes by car from Hamamura-Shikano-Onsen IC on the San'in Expressway, or 10 minutes by bus from JR Hamamura Station to 'Imamachi'. Handy on the way back from the Tottori dunes or Uradome coast.
A cure-bath founded in the Meiji era, tucked in the hills of Misato, Shimane, up a tributary of the Gō River. The spring bubbles up directly through gaps in the wooden floor of the tub — 'footspring' water that onsen devotees rank among the finest sources in western Japan. The carbonated iron-bicarbonate water is tepid at around 34 °C, faintly yellow-brown, and coats the body in tiny bubbles. There is one small wooden tub each for men and women, no washing area, soap and shampoo are forbidden, and bathing is limited to an hour: this is a place purely for soaking. Afterwards you can warm up in a heated goemon iron-kettle bath. Adults ¥500; open 08:00–18:00 April–October (last entry 17:00) and 08:00–17:00 November–March (last entry 16:00), closed Thursdays. Room rest is available. With the Sankō rail line gone, driving is realistic: about 1 hour from JR Gōtsu Station or 50 minutes from Ōasa IC on the Hamada Expressway, with a narrow mountain road at the end. Not for those wanting facilities, but unforgettable for those who care about the water itself.
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.
The communal bath at the centre of Yuwaku Onsen, Kanazawa's 'back parlour', about 50 minutes by bus from Kanazawa Station. The spa dates back 1,300 years, prospered as the cure resort of the Kaga lords, and is remembered as where the Taishō-era artist Takehisa Yumeji stayed with his lover; the name comes from a legend of an egret healing its wounds here. Inside, the wood-rich building is calm, with clear, smooth sodium-calcium-chloride water served fairly hot in a simple bathroom (no open-air bath or sauna). Cheap at ¥490 for adults and ¥130 for children, and open 07:00–22:00, it suits a bath-hopping circuit from the ryokan or a finish to a Kanazawa day. Closed the third Thursday (plus occasional days). Combine with the Gyokusen Lake path, the Yumeji museum and the inns' restaurants. Known as the setting of the anime 'Hanasaku Iroha', the village holds the Bonbori lantern festival in October. About 30 minutes by car from Kanazawa-Morimoto IC; parking is limited.
One of the few natural-spring bath complexes on Okinawa's main island, on Route 58 in Ginowan next to the MEGA Don Quijote, about 30 minutes by car from Naha. The tea-brown water pumped from underground is a salty chloride spring that warms you well; besides the indoor bath, carbonated bath, sauna and cold plunge there is a pleasant garden open-air bath among tropical planting. Bedrock baths, private family baths, a recliner lounge and an inexpensive canteen round it out, and towels and shampoo are included so you can come empty-handed. Entry: adults ¥1,500, junior/senior high ¥1,000, children ¥750; open 07:00–23:00 (last entry 22:00), every day. Close to Chatan's American Village and the Ginowan beaches, it is handy on a rental-car trip or as a proper wash after a day in the sea — many divers stop by on the way home. 200 parking spaces.
A day spa on Route 202 in Karatsu, right beside Niji-no-Matsubara, one of Japan's three great pine groves, and an easy 10-minute walk from JR Niji-no-Matsubara Station. The mildly alkaline simple spring is used free-flowing and lives up to its 'beauty bath' name with a silky feel. There are tepid and hot tubs, an open-air bath, sauna and cold plunge, plus three private family baths (rock, barrel and so on; extra charge, booking until 20:00). Adults ¥800, children ¥450; open 10:00–22:00 (last entry 21:30), closed the third Thursday (open daily in January, February and August; special closure on December 31). The restaurant serves set meals with Karatsu fish, and as a pilgrimage spot for the anime 'Yuri!!! on Ice' the building has a fan display corner. Fits between Karatsu Castle, the Yobuko morning market and a drive along the pines, or as the finish to a day trip from Fukuoka — about an hour by car from the city. 50 parking spaces.
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.
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 big bath complex on the Kanzaki River in Toyonaka, about 20 minutes north of Umeda, whose main draw is an authentic Korean-style jjimjilbang — rare in Kansai. Sauna fans rate it highly for the large natural-spring open-air bath, cut-stone bath, pot baths, a sauna with löyly sessions every two hours, cold plunge and plenty of chairs and loungers for outdoor rest. The extra-charge 'Bijōbō' zone offers several low-temperature sauna rooms at 40–70 °C and a dome-shaped hanjeungmak at around 100 °C — Korea's steam-bath culture in Osaka. Entry: adults ¥900 on weekdays, ¥1,000 on weekends and holidays; children ¥500/¥550. Open 10:00–02:00 (last entry 01:00), every day. Besides 1,200 free parking spaces, free shuttle buses run from Hankyū and Kita-Osaka Kyūkō stations, so it is easy without a car. Restaurant, body care and relaxation rooms on site; being close to Itami Airport, it is a good place to kill time before or after a flight. Very busy on weekends and holidays.
The oldest naturally rising spring of Hinatayama Onsen, the spa district along the Amori River in Hayato, Kirishima, about 15 minutes by car from Kagoshima Airport. Saigō Takamori is said to have favoured it between hunts, and locals call it 'Segodon's bath'. It is unstaffed — you drop your fee in the box at the entrance — and the price is frozen in the Shōwa era: ¥250 for adults, ¥100 for children. Inside is a simple indoor bathroom with two tubs, hot and moderate, filled free-flowing with clear, slippery bicarbonate water; there is a drinking fountain of the spring too. No open-air bath or restaurant, but it opens 06:00–21:00 (last entry 20:30) and a room-only lodge next door costs ¥1,800 including the bath — a boon for travellers. Closed the fourth Monday. About 5 minutes on foot from JR Hinatayama Station; 10 parking spaces. For anyone wanting an unadorned everyday Kagoshima bath before or after Kirishima Shrine or the airport.
The public bath at the centre of Tsuchiyu Onsen, a spa village in the fold of the Azuma range about 40 minutes by bus from Fukushima Station. Rebuilt in 2018 in fragrant timber, it faces the Arakawa mountain stream. The alkaline bicarbonate water is used free-flowing without heating or recirculation — clear and soft but decidedly hot, so adding cold water to taste is the local custom. Besides separate indoor baths there is a private bath (¥1,500), handy for families and couples. Adults ¥500, children ¥250; open 09:00–21:00 (last entry 20:30), closed Tuesdays (open over New Year). The village has foot baths, workshops making Tsuchiyu kokeshi dolls, the steaming Arakawa source and another communal bath, Kajika-no-yu, so a stroll with a kokeshi-painting session fills a pleasant half day. 82 free parking spaces. About 20 minutes by car from Fukushima-nishi IC, and a convenient gateway to the Bandai-Azuma Skyline.
A day spa beside the 'Kamon Park Shinminato' roadside station in Imizu, on Toyama Bay. Its spring is a dense chloride water said to rank among the richest in Japan in dissolved minerals, with several times the free carbon dioxide of shop-bought bath fizzers, so onsen enthusiasts know it as a genuine carbonated chloride spring. The tea-brown, salty, iron-rich water warms you deeply; there are indoor and open-air baths, a sauna and a cold plunge. What stands out is the long day: an early-morning bath from 05:00 through to midnight (23:00 on Sundays), with cheaper early and late rates. Regular admission is ¥970 for adults (¥1,020 weekends and holidays), ¥750/¥780 early or late, ¥520 for children. Closed Mondays (open if a holiday, then closed the next weekday) and January 1. Easy to pair with the Shinminato Bridge, Kaiwo Maru Park and seafood at the Shinminato Kittokito market; about 10 minutes by car from Kosugi IC or 20 minutes by community bus from JR Kosugi Station.
A municipal day bath in the middle of the Yubara Onsen village in northern Okayama, a few minutes' walk from the famous riverside open-air 'Sunayu'. Yubara has a thousand-year history and copious water; this is its source bath, and the pH 9.3 alkaline simple spring is a slippery 'beauty water'. The three-storey building has souvenirs on the ground floor and baths on the first: for each sex an indoor bath, jacuzzi and sauna, plus a barrier-free bathroom usable by elderly and wheelchair guests, which can also be hired as a family bath (¥3,000 per hour for up to three). There is no view, but travellers value it as the place to wash and warm up properly after the mixed Sunayu. Adults ¥800, children ¥400; open 10:00–21:00 (last entry 20:30), closed Wednesdays. A tatami rest room and relaxation corner are provided. About 5 minutes by car from Yubara IC on the Yonago Expressway, or 40 minutes by bus for Hiruzen Kōgen from JR Chūgoku-Katsuyama Station to 'Sayama' then 5 minutes on foot.
A small wooden day bath in Dai Onsen, an old spa hamlet where inns huddle along a narrow valley beyond Hanamaki Onsen. Dai Onsen, over 600 years old, is known for its many hot sources, and here too the free-flowing water is served hot in a little bathroom — a tub that holds ten at a squeeze and five washing stations. There is no lounge or shop, but it opens every day from 06:00 to 22:00 (last entry 21:30) and charges only ¥480 for adults and ¥250 for children — a place that made news by cutting its price when everyone else was raising theirs. Shampoo and body soap are provided, and a handmade soba house next door serves lunch (booking needed). Under 10 minutes by car from Hanamaki Onsen, about 20 minutes by taxi from JR Hanamaki Station; 30 parking spaces. An easy way to feel the cure-resort air of Dai Onsen, a world apart from the big hotels of Hanamaki.
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.
The oldest of the communal baths surviving in the spa town of Kaminoyama, a former castle and post town about 10 minutes on foot from Kaminoyama-Onsen Station on the Yamagata Shinkansen. Moved to its present site in 1624, it is said to have been used by the Zen master Takuan. The big tub is split into hot and tepid halves, filled free-flowing with clear sodium-calcium-chloride-sulphate water. With its flagstone washing area and old-style attendant's counter, it charges an astonishing ¥150 for adults and ¥100 for children (hair washing ¥100 extra), and the tatami hall upstairs can be used for a day's rest for ¥300. Open 06:00–22:00 (from 06:30 December–February; last entry 21:30), every day. Take a morning or evening dip with locals while touring Kaminoyama Castle, the samurai-house street and the town's five foot baths. About 25 minutes by car from Yamagata city, 40 minutes from Zaō Onsen. No soap is provided, so bring your own; park in the shopping-street car park opposite.
The public bath at the heart of Yunomine Onsen, one of Japan's oldest springs, where pilgrims purified themselves before Kumano Hongū Taisha. The building, renovated in 2022, also serves as reception for the World Heritage 'Tsuboyu'. There are three bathrooms: the 'Ippan-yu' with hot and tepid tubs (adults ¥400, shampoo provided), the concentrated 'Kusuri-yu' filled with undiluted source water (¥600, no soap allowed) and a 30-minute private family bath (¥700), all sulphur-scented sodium-bicarbonate-chloride water ranging from milky to clear. Tsuboyu (¥800, 30-minute slots) can mean a wait of hours when busy, so the clever order is to take a number and warm up in the public bath first. Open 06:00–21:00 (last entry 20:30), irregular cleaning closures. The village also has the 'Yuzutsu', a 90 °C source where you boil eggs and vegetables, and is the trailhead of the Dainichi-goe section of the Kumano Kodō. About 2 hours by bus from JR Kii-Tanabe or Shingū stations to 'Yunomine Onsen', right by the stop; 46 parking spaces.