
Photo: Masashi Taomoto · CC BY 3.0 · Wikimedia Commons
上河内温泉 is a hot spring town in Tochigi, Japan. The water leaves the ground at 50.1°C, hot. It measures pH 8.9 — mildly alkaline, the slippery kind. Officially the water is classed as chloride spring and sulfate spring. Its sources put out around 400 litres a minute.
Salty water. The salt leaves a thin film on the skin, so you stay warm well after leaving the bath.
Clear water with a faintly bitter taste. Known for holding heat.
Figures from the town's Japanese Wikipedia article.
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