Yubara Onsen Sunayu

Sunayuriverbed onsenfree bathYubaramixed bathing

Okayama · Maniwa

35.2053°N, 133.7327°E

Sunayu is a set of open-air baths on the bed of the Asahi river, directly under the 73-metre wall of the Yubara dam, where hot water comes up through the sand and gravel of the riverbed itself. There is no building. Stones ring three pools called the beauty bath, the child-bearing bath and the long-life bath, and the whole thing is free, mixed and open at any hour of any day.

A national ranking of open-air baths published by the hot spring association put it at the top of the western list, and it has held that reputation for decades. Monks are said to have opened it in the middle Heian period and the first lord of Tsuyama had the springs walled with stone. Bathing here in falling snow, with the dam wall above and the river running past a metre away, is the reason people drive four hours for it.

Essential Information

Opening Hours

Open 24 hours

Closed: Open year-round; drained for cleaning once a week — confirm the current slot locally

Entrance Fee

Free | Rental bathing garment charged separately in the town

Best Season

December–February for snow on the dam wall and steam off the river

Visit Duration

45 minutes – 1 hour

Getting There

Access Information

Yubara Onsen, Maniwa City, on the riverbed beneath Yubara Dam. About 25 minutes by car from Yubara Interchange on the Chugoku Expressway; buses run from Chugoku-Katsuyama Station. Free and open 24 hours a year-round. Mixed bathing: women generally use a rental bathing garment and men wrap a towel. Changing facilities are minimal and there is a weekly cleaning slot when the pools are drained — confirm the current day and time locally.

Insider Guide

Premium

**Mixed bathing, and that is not a formality.** Women almost always use a rental yugami bathing garment, available in the town. Turning up without knowing this is the standard mistake. **Winter is when it is worth the drive.** Snow on the dam wall, steam off the river, and the pools stay hot. Summer is pleasant and unremarkable. **It is drained and cleaned weekly.** There is a fixed slot when the pools are empty. Ask at any inn in the town rather than arriving on spec. **Almost no privacy screening.** The baths sit on an open riverbed under a road. This is a public bathing place in the oldest sense and people treat it matter-of-factly. **Yubara has indoor baths too.** A dozen inns along the river offer day bathing if the open riverbed is not for you, and the town runs a stamp scheme across them. **Hiruzen is 40 minutes north.** The highland, the Jersey herds and the yakisoba make the natural pairing for an overnight in this corner of the prefecture.

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