Photo: Soica2001 (talk) · Public domain · Wikimedia Commons
Meakan onsen is a hot spring town in Hokkaido, Japan. The water leaves the ground at 50–80°C, hot enough that it has to be cooled before anyone can get in. Officially the water is classed as sulfur spring.
The classic rotten-egg smell and milky white water. It can tarnish silver jewellery, so take it off.
Figures from the town's Japanese Wikipedia article.
43.3953, 143.9836 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.