Bessho Onsen, Ueda, Nagano Prefecture
Ishi-yu Public Bath
A natural-rock bathing space with a strong connection to Sanada history and the old hot-spring town. For fully source-flowing water, Daishi-yu is the clearer choice.
Check before bathing
- Opening hours
- 06:30–21:30; last admission 21:00. Normally closed Tuesdays.
Spring & water temperature
- Spring-source temperature
- About 50.6°C for No. 4 spring.
- Bathing temperature
- Not published.
- Spring source
- Bessho Onsen No. 4 spring.
- Spring classification
- Simple sulfur spring.
- pH
- No. 4 spring analysis from 2014: pH 8.7 at the emergence point and 8.92 in the laboratory.
- Flow rate
- About 900 L/min for the shared No. 4 spring; this is not the amount delivered exclusively to Ishi-yu.
- Water handling
- No. 4 supplies Ishi-yu. The property district describes the bath as source-flowing with circulation filtration, so it should not be simplified to fully untreated source flow.
- Analysis date
- 2014
Bathing indications
General Bessho Onsen bathing indications are retained from the property district's public information. They are not a promise of treatment or beauty effects.
Current admission is ¥300 for adults, ¥100 for elementary-school children and free for younger children. The bath is set at a lower level and is known for its natural-rock interior.
How to read a bath profile
Spring-source temperature and actual bathing temperature are kept separate. Each score is shown independently for comparison rather than collapsed into one overall score.
