Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Fukiage Onsen in Hokkaido is a hot spring in the Sorachi Subprefecture region of central Hokkaido, situated in an area of volcanic activity associated with the Daisetsuzan volcanic system that underlies much of the geothermal activity of Hokkaido's interior. The Sorachi region of Hokkaido was historically an important coal mining zone whose underground geology has been intensively studied, and the volcanic activity that produced both the coal-bearing rock formations and the hot spring resources of the region reflects the complex geological history of this central Hokkaido district. The thermal bathing facilities of Fukiage Onsen provide the community of this volcanic highland region with access to the geothermal resources generated by the same underground volcanic systems that have shaped the landscape of central Hokkaido since the island's volcanic formation.
Insider tip — Fukiage Onsen on the slopes of the Tokachidake volcanic range in central Hokkaido is a famous free open-air rotenburo — wild natural hot pools set amid the mountains of the Daisetsuzan National Park, Japan's largest national park. The sulfurous springs draw on the active volcanic geology of the Tokachi peaks, allowing bathers to soak in the open air surrounded by alpine wilderness, deep winter snow, and the volcanic drama of Hokkaido's mountainous interior.