小森温泉 is a hot spring town in Okayama, Japan. The water leaves the ground at 28.1°C, cool enough that the baths here are usually reheated. Officially the water is classed as simple spring.
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.
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