Rich in active gases or metals — a strong mineral character.
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
SoufreSulfuresSulfates
Aurora Onsen is a hot spring in Hokkaido whose name evokes the aurora borealis, the northern lights that occasionally illuminate the night skies of northern Japan on clear winter nights, connecting the theatrical beauty of natural atmospheric phenomena with the restorative experience of soaking in sulfurous volcanic waters under the stars. Hokkaido's northerly latitude and its clear continental winter skies give it the best chance in Japan of witnessing the aurora, particularly in the Tokachi and Okhotsk regions where minimal light pollution allows the night sky to reveal its full astronomical splendor. The sulfurous volcanic waters of Aurora Onsen provide the warming and skin-beneficial bathing characteristic of Hokkaido's volcanic thermal sources, complementing the natural wonder of stargazing and potential aurora viewing in one of Japan's finest environments for experiencing the beauty of the northern winter sky.
Insider tip — Aurora Onsen sits at the edge of Akan Caldera in eastern Hokkaido, fed by the same volcanic activity that produced the luminous blue-green Lake Akan and its famous marimo moss balls. The strongly sulfurous waters emerge at high temperature from fumarolic vents and are traditionally used by the Ainu indigenous people for healing. The outdoor bath faces a dense primeval forest of Yezo spruce that darkens quickly at dusk, making evening bathing here feel genuinely wild. On clear winter nights the aurora borealis occasionally shimmers above the treeline, earning the spa its evocative name.