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.
A vast garden bath hall fed by 14 sources at 1,400 litres a minute, with four water types — sulfur, alum, saline and iron — in one place. The central pool is mixed-gender (women-only hours; bathing garments allowed).
The signature of Beppu's giant hilltop hotel: a five-tiered open-air bath cascading toward Beppu Bay, spectacular at night and dawn. Day tickets include the swimsuit-friendly outdoor spa pool 'Aqua Garden'.
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 huge boulder-lined mixed open-air bath on the Gamata riverbed, looking up at the Northern Alps and a suspension bridge. Open only late April to the end of October; swimwear or bathing gowns allowed. Pay a cleaning donation of about ¥300.
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 large resort hotel above the gorge. The basement bathhouse Yusuikyo is open to day visitors on weekdays only, with a combined ticket for the indoor water park 'Lagoon' — handy for families on rainy days. Weekends and holidays are guests only.
A natural open-air bath on the Asahi River gravel bed right below Yubara Dam, where water bubbles up through the riverbed itself — ranked the 'western grand champion' of Japan's rotenburo. Three pools at different temperatures; mixed, free and open 24 hours. Only a simple changing hut, so women are advised to wear a bathing garment (sold and rented in town). Closed Wednesday mornings for cleaning. Photography strictly forbidden.
A 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.
At Kawayu, where 73°C spring water bubbles up through the bed of the Ōtō River, a giant outdoor bath is created every December to February by damming the river. Roughly 50 by 15 metres — big enough for 'a thousand people', as the name says — it's tempered to perfection by the river's cold flow. Free (donation box), 6:30–22:00, swimwear required, open to everyone. Bathing is suspended in bad weather or high water and opening dates shift from year to year. In summer you can dig your own pool in the gravel. Combine with Yunomine and Watarase for the three Hongu baths.
A resort bathing complex next to the American Village in Chatan, central Okinawa, facing Sunset Beach. The sodium-chloride 'Chatan Onsen' water from 1,400 m fills an indoor bath hall and an open-air bath overlooking the sea, and there is also a swimsuit zone with an outdoor hot-spring pool, jacuzzi and sauna, with free passage between pool and beach. Adults ¥1,800, children ¥800 (a cheaper morning-bath plan exists); baths open 07:00–23:00 (last entry 22:00), outdoor facilities 10:00–21:00, no closing days apart from one maintenance day a year. Loungewear and towel rental and a restaurant are available; about 40 minutes by car from Naha. Rinse off the salt after a day in the sea and soak while the sun sets — a very Okinawan day.
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.
A hot-spring resort on the Rurikei plateau in Nantan at about 500 m, roughly an hour by car from Kyoto city, at the entrance to the scenic Rurikei gorge trail. Formerly 'Kyoto Rurikei Onsen for REST RESORT', it was renovated and renamed in 2025. The water is a mildly radioactive radon spring; besides the gender-separated 'Ruri-yu' halls, open-air baths and single-person ceramic pot baths, there is a swimwear zone where couples and families bathe together, along with a pool and saunas. Day admission (including the pool and swimwear area) is ¥800 for adults and ¥400 for children on weekdays, ¥950 and ¥500 on weekends and holidays; towel set ¥300, swimwear rental ¥400. Bedrock baths and the lantern terrace cost extra. Open 11:00–20:00 on weekdays and 10:00–21:00 on weekends and holidays, every day. Barbecue, a kids' area, the GRAX glamping site and a hotel share the grounds, and at night the 'Synesthesia Hills' illumination is a draw. Keihan Kyoto Kōtsū bus to 'Rurikei Onsen', or about 30 minutes by car from Kameoka IC.
A hot-spring complex on a rise in Haruno, Kōchi city, about 30 minutes by car from Kōchi Station, looking out over rice fields. Its big open-air bath fed by an abundant natural spring is the draw, with an indoor bath, a sand bath that warms you to the core, and in July–August a swimwear spa zone (pair baths, a children's spa and so on — ten in all), so families are many. Day bathing: adults ¥700, children ¥300, over-65s ¥500; open 10:00–21:00 (last entry 20:15), every day apart from occasional maintenance. The Haru Noie restaurant serves a weekly lunch, and a lodging wing with open-air-bath rooms starts at ¥8,650 with breakfast; being near the Haruno sports park it also hosts training camps. About 40 minutes by car from Kōchi Ryōma Airport, or 15 minutes on foot from the terminus of the Tosaden bus for JA Haruno; 60 parking spaces. A rare large open-air bath within Kōchi city, easy to fit between Katsurahama and the Niyodo Blue river.
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.
Miyakojima is often assumed to have no hot springs, yet inside the Shigira Seven Miles Resort on the island's south coast lies one of Japan's southernmost and westernmost natural onsen. Golden sodium-chloride water rises undiluted from 1,250 m underground into separate men's and women's open-air baths and saunas wrapped in subtropical greenery, plus a swimsuit 'jungle pool' and lookout bath where families and couples can soak together – there are even floats for a full resort mood. Adults (12+) pay ¥2,000 and children 4–11 ¥1,000; guests of Shigira Resort hotels pay ¥1,600/¥800. Swimsuit rental is ¥510 and towels are rented for a fee. Open 11:00–22:00 (last entry 21:30), from 12:00 between mid-November and mid-March, every day, with a restaurant and relaxation salon on site. About 15 minutes by car from Miyako Airport, with resort shuttle buses in the evening. Combine it with Shigira Beach, south-coast sunsets and stargazing.