21 Facilities5 Onsen towns
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.
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.
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.
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.
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.
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.
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.
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-bathing facility attached to Ikaho Grand Hotel. Ikaho's famous tea-brown 'golden water' can be enjoyed in an open-air bath looking over forest green and a bright great bath with skylights. It stays open 10:00–22:00 (last entry 21:00), and entry taken by 15:00 is ¥743 for adults and ¥440 for ages 3 to elementary, rising to ¥1,073 and ¥660 after 15:00 (bathing tax included in both). Closed the second Wednesday (the next day if a holiday). Towels with the hotel's name are sold for ¥275, bath towels rented for ¥220 and yukata for ¥220. Free parking for 250.
A large inn in Minakami, formerly Gensen-yu no Yado Matsunoi, now part of the Oedo Onsen Monogatari Premium line. Three open-air baths face a garden of 10,000 tsubo, Akane-no-yu, Aono-yu and Wakaba-no-yu, with great baths as well. Akane-no-yu switches between men and women, and the men's open-air bath has a barrel sauna. Day bathing needs no reservation and runs 7:00 to 10:00 and 15:00 to 24:00 with last entry at 22:00, at 1,150 yen for adults on weekdays, 1,400 yen on weekends and holidays and 1,600 yen on peak days. Towels rent for 330 yen. People with tattoos may use the great baths only if they are fully covered with the designated cover stickers, which are sold on site.
A town-run day-bathing facility at the entrance to Shima Onsen. Its sodium-calcium chloride-sulfate spring fills open-air baths overlooking the Shima River (Hyotan-no-Yu, Oborozuki-no-Yu) and large indoor baths (Ogi-no-Yu, Yahane-no-Yu).
A venue dedicated to Kusatsu's signature traditional art - the Yumomi & Dance show - standing right in front of the onsen town's symbol, the Yubatake. To cool the roughly 50°C spring water without diluting it, boards about 1.8 m long are used to stir the bath: this yumomi technique is a Kusatsu tradition, performed by women in matching costumes singing Kusatsu-bushi folk songs and dancing. Shows run six times daily (9:30, 10:00, 10:30, 15:30, 16:00, 16:30), each about 20 minutes; admission is 600 yen for adults and 300 yen for elementary students (some sources list 700 yen - confirm locally). On Sundays and Mondays you can join the hands-on yumomi experience (from 300 yen). This is a show venue, not a bathing facility - pair your visit with the nearby Sainokawara open-air bath or Otaki-no-Yu. About 5 minutes on foot from the Kusatsu Onsen Bus Terminal.
A single ryokan beside the Takaragawa River deep in the Minakami onsen area of Gunma. Its crowning feature is a colossal open-air bath complex totalling about 470 tatami mats, fed by four sources flowing 1,800 litres a minute, free-flowing - a world-class onsen chosen as one of Japan's best by overseas guidebooks. Along the river stretch the mixed-bathing Maka-no-Yu (~120 mats), Kodakara-no-Yu (~200 mats) and Hannya-no-Yu (~50 mats), joined by the women-only Maya-no-Yu (~100 mats); bathing garments are mandatory for mixed bathing (rentals available for women). The water is a colourless alkaline simple spring. Day bathing runs 10:00-16:30 (last entry 16:00) at 1,500 yen for junior-high and up. All four sources are enjoyed with no heating or recirculation - a wild riverside bathing experience.
A free public bath in Jizo Square, about a 3-minute walk along narrow lanes from the Yubatake, the landmark of Kusatsu Onsen in Gunma. Beside it stand a small yubatake where the spring wells up and the eye-washing Jizo, said to grant relief for eye ailments; at night the footbath and mini yubatake are lit up for a dreamlike scene. The current building is a modern wooden hall rebuilt in 2006, with modest gender-separated indoor tubs that fill up at five or six bathers. Alongside Shirahata-no-Yu and Chiyo-no-Yu it is one of the three Kusatsu public baths open to visitors - said to be the hottest of the three. The water is a free-flowing sulfur-bearing aluminum sulfate-chloride spring (hydrogen sulfide type), and bathing is free. Open 8:00-22:00 year-round (occasional maintenance closures). Locals use it heavily at certain hours, so bathe courteously.
A ryokan founded in the Hoei era (around 1710), just 50 metres from Ikaho Onsen's iconic stone staircase in Shibukawa, Gunma. One of only a handful of inns in Ikaho holding its own spring rights, it fills every bath with 100% free-flowing Kogane-no-Yu - the iron-rich, tea-brown famous water - with no added water. The two main baths, Gekko-no-Yu and Orizuru-no-Yu, alternate between genders, and there are private family baths too. Day bathing is weekdays only, 15:00-19:00 (last entry 18:00), 1,130 yen for adults and 756 yen for children. The 40-room inn blends Taisho-era charm with modern comfort, making it a convenient base for strolling the stone steps. A shuttle runs between the dedicated parking lot and the inn. Ikaho Ropeway's Miharashi Station is within walking distance, with views over the Haruna foothills.