Otari Onsen

Otari Onsen is a mountain thermal spa in the village of Otari in the far northwest of Nagano Prefecture, where the high valleys of the Hakuba and Kurobe mountain systems—part of the Northern Japan Alps (Hida Mountains)—descend toward the Sea of Japan coast of Niigata Prefecture in some of the country's most dramatically snowbound winter terrain. The siliceous mineral waters warm skiers and alpine trekkers who explore the adjacent Tsugaike Kogen and Hakuba ski areas from the Otari valley base, providing restorative thermal immersion after days spent in powder-snow conditions generated by moist Japan Sea winter air masses colliding with the alpine ridge. The wild Himekawa River gorge, the Genga limestone caverns, and the Otari Natural Science Museum—dedicated to Jurassic-era marine fossils found in the surrounding mountains—give this remote mountain onsen an unexpected scientific depth beneath its alpine beauty.