Hirayu Shirakaba Onsen
- Location
- Hirayu, Gifu (Okuhida, Northern Alps), Japan
- Water type
- sulfurous
- Temperature
- 44 °C
- pH
- 6.5
Water profile
Relaxing — deep, immediate muscle release.
Rich in active gases or metals — a strong mineral character.
Soft water — natural, classic buoyancy.
Hirayu Shirakawa Onsen occupies a position of remarkable natural drama in the Okuhida Onsengo cluster, deep in the mountainous interior of Gifu Prefecture at the northern edge of the Japanese Alps. The Hirayu area sits at over 1,000 metres elevation, surrounded by the white-crested peaks of the Northern Alps, and in winter the entire landscape transforms under heavy snowfall — a setting that makes the outdoor rotenburo baths one of the great sensory experiences of Japanese mountain travel.
The spring is sulfurous, emerging at a vigorous 44 °C with a mildly acidic pH of 6.5, producing water with the characteristic pale translucence and mineral edge of high-altitude volcanic springs in the Japanese Alps. The heat at this temperature is immediately penetrating, warming the body against the alpine chill with notable efficiency. Hirayu Shirakawa Onsen is part of the broader cultural corridor connecting the Okuhida mountains to the nearby UNESCO-listed gassho-zukuri villages, making this one of Japan's most geologically and culturally layered onsen experiences.