Kawayu Onsen 川湯温泉
pH between 0.8 and 2.4, some of the most acidic water in Japan: it cures everything ‘except lovesickness’.
Kawayu, whose name literally means ‘hot river water’, is a hot spring village in the town of Teshikaga, fed by the waters of nearby Lake Mashū.
Hokkaido
Teshikaga-chō Yakuba Kawayu-shisho-mae (弟子屈町役場川湯支所)