Yudanaka Onsen, Yamanouchi, Nagano Prefecture
Yudanaka Oyu Public Bath
Now included in Yudanaka's 2026 outdoor-bath pass, this is a good way to experience local communal-bath culture. Do not treat resort-wide spring averages as measurements for this individual bath.
Check before bathing
- Opening hours
- Use is available through the 2026 Yudanaka Onsen outdoor-bath pass. Oyu's listed access window is 10:00–17:00; it may be unavailable on bath-cleaning days and other specified dates.
Spring & water temperature
- Spring-source temperature
- Not published for Oyu. Yamanouchi Town's 65–93°C range describes Yudanaka Onsen overall and is not substituted for this bath.
- Bathing temperature
- Not published.
- Spring source
- Yudanaka Onsen; the individual spring used by Oyu is not named.
- Spring classification
- At the resort level, Yudanaka's main spring types are chloride and sulfate springs. A current chemical classification for Oyu itself is not published, so resort-wide averages are not treated as this bath's analysis.
- pH
- Not published.
- Flow rate
- Not published.
- Water handling
- The 2026 official outdoor-bath pass confirms access to Oyu. Pool-specific water addition, heating, circulation, disinfection and source-flow conditions are not published in the current pass information.
Bathing indications
Yamanouchi Town lists general bathing indications for Yudanaka Onsen, but Oyu's latest individual analysis is not public. Resort-wide indications are not presented as treatment claims for this bath.
The 2026 pass costs ¥1,800 for adults and ¥1,000 for children and covers Oyu, Watanoyu and Kaede-no-Yu. Oyu is available 10:00–17:00, subject to bath-cleaning and other closure dates. The pass price is not a single-entry price for Oyu.
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.
