Photo: Nissy-KITAQ · CC BY-SA 3.0 · Wikimedia Commons
Yoshii Onsen (Fukuoka) is a hot spring town in Fukuoka, Japan. The water leaves the ground at 36–42°C, hot. Officially the water is classed as iron spring. 3 inns take visitors here.
Turns reddish brown as the iron meets air. The water is clear at the source.
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.



Figures from the town's Japanese Wikipedia article.
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.