Senko Onsen
Shimosuwa, Nagano, Japan
- Location
- Shimosuwa, Nagano, Japan
- Water type
- iron-rich
- Temperature
- 38 °C
- pH
- 6.3
Water profile
Thermicity
Neutral
LowHigh
Soothing — neither hot nor cold, perfect balance.
Mineralisation
Bio-active
LowHigh
Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
FerBicarbonatesManganèse
Senko Onsen, in Shimosuwa, Nagano prefecture, stands out for its iron-rich water with a pH of 6.3, at 38°C. An indoor bath, an outdoor rotenburo bath and a sauna are available on site.
Insider tip — Senko Onsen is a historic bathhouse in Shimosuwa, the southern gateway town to Suwa Lake in Nagano Prefecture. Iron-rich mineral waters bearing a subtle metallic fragrance have drawn pilgrims and travelers on the old Nakasendo and Koshu-kaido roads for centuries. The facility maintains a faithful old-fashioned sento atmosphere with affordable entry. Walking the preserved post-town streets after a soak is an essential piece of the Shimosuwa experience.
Nearby
Frequently asked questions
How hot is the water?
The water is neutral here, around 38 °C — a perfect balance, neither too hot nor too cold.
What type of water is found here?
This spot features iron-rich water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année (idéal automne-hiver).