Kurami Onsen is a hot spring town in Shizuoka, Japan. The water leaves the ground at 18°C, cool enough that the baths here are usually reheated. It measures pH 9.8 — strongly alkaline. Officially the water is classed as sulfur spring. 3 inns take visitors here.
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.
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.