
Photo: Yas · CC BY-SA 3.0 · Wikimedia Commons
Nurukawa Onsen is a hot spring town in Aomori, Japan. The water leaves the ground at 58°C, hot. Officially the water is classed as chloride spring.
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
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.