Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
CalciumSulfatesMagnésium
Maruseppu Onsen flows with sulfate-rich thermal waters in Hokkaido, Japan's northernmost main island, where the volcanic geology of the island's interior produces springs of considerable mineral intensity and distinctive character. The sulfate composition of this spring's water is traditionally associated in Japanese and international thermal culture with relaxation and recovery, making it particularly appreciated by those engaged in active outdoor pursuits in Hokkaido's challenging mountain terrain. Maruseppu Onsen represents the grounding, restorative dimension of Hokkaido's onsen culture, where naturally heated sulfate waters have provided warmth and comfort for generations of farmers, loggers, and mountain travelers in one of Japan's most demanding natural environments.
Insider tip — Maruseppu Onsen sits in the vast forests of the Okhotsk region in northeast Hokkaido, where sulfate-rich waters emerge in a landscape of birch groves, wetlands and wilderness. The pale milky water has a warming quality well suited to the long Hokkaido winters and is valued locally for its joint-soothing properties. This remote spring sees very few foreign visitors, making it one of the most genuinely off-the-beaten-path onsen experiences in Japan. Red-crowned cranes, a symbol of longevity, are occasionally spotted in the surrounding marshland.
