Koakasawa Onsen
Koakasawa Onsen is a hot spring town in Nagano, Japan. The water leaves the ground at 45°C, hot. It measures pH 6.57 — close to neutral. Officially the water is classed as chloride spring and iron spring.
The water here
Chloride spring
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
Iron spring
Turns reddish brown as the iron meets air. The water is clear at the source.
Things to see nearby
Places from Wikidata, photographs from Wikimedia Commons. Distances are in a straight line from the town.
With tattoos
Many public baths still turn away visible tattoos, and the rule is set by each bath, not by the town. The reliable way round it is to bathe privately: a room with its own open-air bath, or an inn with a private bath you can book for yourselves.
Where to stay
Hot spring towns nearby
Similar water elsewhere
The numbers
- Water temperature
- 45°C
- pH
- 6.57 (close to neutral)
- Address in Japanese
- 長野県下水内郡栄村小赤沢
Figures from the town's Japanese Wikipedia article.
Where it is
36.8661, 138.6380 — open the map
Read more
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.