Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Hiroo Onsen is found in Hiroo, a small Pacific coastal town at the southern edge of the Tokachi Subprefecture in southeastern Hokkaido, a community set between the broad agricultural plains of Tokachi and the wild Pacific coast near Cape Erimo — the dramatic windswept headland at the southern tip of the Hidaka Mountains that juts into the Pacific and is consistently among the windiest locations in Japan, with average wind speeds that have made Erimo-misaki synonymous with Hokkaido's untamed coastal weather. The surrounding coastal waters are rich in marine life including harbor seals, sea lions, and various Pacific seabirds that breed on the rocky islets and sea stacks of this productive cold-water coast. The onsen here draw on geothermal resources from the Hidaka volcanic belt, offering silica-rich mineral bathing in a coastal community where the agricultural tradition of the Tokachi plain meets the wild Pacific frontier of Hokkaido's southeastern shore.
Insider tip — Hiroo Onsen sits in the coastal town of Hiroo in the Tokachi subprefecture of southeastern Hokkaido, facing the Pacific Ocean along a wild and largely undeveloped shoreline. The sodium-chloride spring water at 42°C delivers a briny, warming soak in keeping with the maritime character of this remote fishing and farming community. Hiroo is the gateway to the rugged Erimo Cape, where Steller sea lions haul out on the rocky shores, and the onsen provides welcome warmth after windswept coastal excursions. The town's isolation makes this a truly off-the-beaten-path onsen destination.