平舘不老不死温泉 is a hot spring town in Aomori, Japan. The water leaves the ground at 40°C, comfortably warm. Officially the water is classed as sulfate spring.
Clear water with a faintly bitter taste. Known for holding heat.
Figures from the town's Japanese Wikipedia article.
41.1498, 140.6323 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.