二口温泉 is a hot spring town in Miyagi, Japan. The water leaves the ground at 26–27°C, cool enough that the baths here are usually reheated. It measures pH 9.5 — strongly alkaline. 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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