
Photo: NY066 · CC BY-SA 3.0 · Wikimedia Commons
日奈久温泉 is a hot spring town in Kumamoto, Japan. The water leaves the ground at 30–40°C, comfortably warm. It measures pH 8 — mildly alkaline, the slippery kind. Officially the water is classed as simple spring. Its sources put out around 100 litres a minute. 15 inns take visitors here.
Mild and low in dissolved minerals. Usually clear and gentle on the skin, which is why these baths are often recommended for first-timers.
Figures from the town's Japanese Wikipedia article.
32.4296, 130.5655 — open the map
Planning a first soak? Read how an onsen stay works, and what to do if you have tattoos.