Genseitei Onsen
Koshimizu, Hokkaido, Japan
- Location
- Koshimizu, Hokkaido, Japan
- Water type
- sodium chloride, thermal
- Temperature
- 39 °C
- pH
- 7.3
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Located in Koshimizu, Hokkaido, Genseitei Onsen offers a soak in thermal sodium-chloride water at 39°C, with an indoor bath, open-air outdoor bath and sauna.
Insider tip — 'Genseitei' (garden of pristine waters) at Koshimizu, on the Okhotsk coast of northeastern Hokkaido near the vast Lake Saroma — Japan's third largest lake. The Sea of Okhotsk sends drift ice to this shoreline in winter, creating extraordinary views from indoor onsen pools. Visit January–March for the drift ice spectacle.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 39 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features sodium chloride & thermal water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.