Photo: ja:User:Si-take. · CC BY-SA 3.0 · Wikimedia Commons
Ōmaki Onsen is a hot spring town in Toyama, Japan. The water leaves the ground at 57.6°C, hot. It measures pH 8.13 — mildly alkaline, the slippery kind. Officially the water is classed as chloride spring. Its sources put out around 304 litres a minute. 1 inns take visitors here.
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.
36.5006, 136.9940 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.