Kyūsuikei Onsen is a hot spring town in Oita, Japan. The water leaves the ground at 50°C, hot. Officially the water is classed as bicarbonate spring and iron spring.
Smooth, slightly slippery water. Often nicknamed bihada-no-yu, the water for beautiful skin.
Turns reddish brown as the iron meets air. The water is clear at the source.
Figures from the town's Japanese Wikipedia article.
33.1731, 131.2158 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.