Akagawa Onsen is a hot spring town in Oita, Japan. The water leaves the ground at 26–28°C, cool enough that the baths here are usually reheated. It measures pH 4.9 — mildly acidic. Officially the water is classed as sulfate spring, carbon dioxide spring and sulfur spring. Its sources put out around 400 litres a minute.
Clear water with a faintly bitter taste. Known for holding heat.
Carbon dioxide spring 二酸化炭素泉
Fine bubbles cling to your skin. Rare in Japan, and usually cooler than other springs.
Sulfur spring 硫黄泉
The classic rotten-egg smell and milky white water. It can tarnish silver jewellery, so take it off.
With tattoos
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.