Kaminoseki Strait Onsen, Kaminoseki, Yamaguchi Prefecture
Hatoko-no-Yu, Kaminoseki Strait Onsen
Do not plan a visit while the renovation closure is in effect. After reopening is confirmed, it should suit drivers around Kaminoseki who want sea views, a sauna, a family bath and dining in one place.
Check before bathing
- Opening hours
- Closed for renovation from 17 August through 31 October 2026 as scheduled. Kaminoseki Town warns that work could extend beyond 31 October, and the facility's 7 September homepage also showed a temporary-closure notice. Reconfirm the reopening date, hours and admission before travelling.
- Tattoo policy
- Not permitted. The current house rules refuse entry to guests with tattoos, including tattoo stickers and body paint.
Spring & water temperature
- Spring-source temperature
- 22.8°C on the facility's current spring-information page.
- Bathing temperature
- Not published. The facility says the water is heated to maintain a comfortable bathing temperature.
- Spring source
- The spring used at Hatoko-no-Yu, drawn from about 1,000 m underground; the current main pages do not publish its formal name.
- Spring classification
- Iron-bearing sodium chloride cold mineral spring; high-salinity and neutral.
- pH
- Not published in the current material summarized here.
- Flow rate
- Not published in the current material summarized here.
- Water handling
- The facility's current spring-information page says the water is heated to bathing temperature, circulated and filtered to protect the resource and maintain hygiene, and treated with sodium hypochlorite for sanitation. Seasonal baths may use bath additives. The outdoor bath uses spring water; the indoor bath uses spring water after manganese and iron are removed. The outdoor bath is not described as unheated, non-circulating or disinfectant-free.
Bathing indications
The facility lists general bathing indications such as neuralgia, chronic digestive and skin conditions, motor impairment, muscle and joint pain, sensitivity to cold, frozen shoulder and recovery after illness. These are not personal treatment guarantees.
The facility confirms heating, circulation filtration and sodium hypochlorite disinfection. The indoor bath has manganese and iron removed from the spring water; some seasonal baths may use additives.
The scheduled renovation closure runs from 17 August to 31 October 2026 and may be extended. Normal prices, hours and bath arrangements should be checked again after reopening.
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.
