Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
CalciumSulfatesMagnésium
Yakeyama Onsen in Itoigawa City, Niigata, sits at the foot of the active volcano Niigata Yakeyama—its name, Burning Mountain, describing the fumarolic activity that has shaped this corner of the Fossa Magna geological zone and that directly feeds the spring's sulfated thermal waters with volcanic minerals from deep within the earth. The spring's dramatic position at the base of an active fire mountain, visible on clear days rising above the spring facilities, gives bathing here a visceral connection to the geological forces powering Japan's entire thermal spring tradition. The spring suspended operations in January 2019, leaving its spectacular volcanic setting as a testament to the raw power that created one of Niigata's most dramatic mountain thermal sites.
Insider tip — Yakeyama Onsen sits at the foot of volcanic Mount Yakeyama in Niigata's Myoko highlands, where calcium-sulfate waters bubble up at a steady temperature suited for après-ski recovery or mountain trekking recuperation. The rugged volcanic terrain and dense beech forests create a dramatic backdrop, and the onsen sees relatively light tourist traffic compared to more famous Niigata spa towns. The sulfate-rich mineral content is particularly effective for relieving muscle soreness. Snowfall in this region is among the heaviest in Japan, making winter visits magical.
