河原の湯・湯前湯4号水 混合泉
Kawara-no-Yu and Yumae-no-Yu No.4 Blended SourceMixed source
Sodium Chloride spring
A sulfur-bearing sodium spring layering sulfate, chloride, and bicarbonate — drawn at 74.8 °C and delivered to the Kawara-no-Yu and Yumae open-air baths at 43.9 °C and 46.6 °C respectively. Near-neutral at pH 7.2, it carries a soft hydrogen-sulfide note with a salty edge from chloride and a touch of bicarbonate softness. The source sits among Japan's hotter natural wellheads, blended in a mixing tank from two parent wells.
- Top-decile hot
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