Handeki Onsen is a hot spring town in Gunma, Japan. The water leaves the ground at 40.8°C, comfortably warm. It measures pH 7.2 — close to neutral. Officially the water is classed as chloride spring. Its sources put out around 293 litres a minute. 1 inns take visitors here with room for about 20 guests.
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
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.