Yaita onsen is a hot spring town in Tochigi, Japan. The water leaves the ground at 76°C, hot. It measures pH 9 — strongly alkaline. Officially the water is classed as chloride spring, sulfate spring and iron spring.
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
Sulfate spring 硫酸塩泉
Clear water with a faintly bitter taste. Known for holding heat.
Iron spring 含鉄泉
Turns reddish brown as the iron meets air. The water is clear at the source.
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.