Ubayu Onsen

Ubayu Onsen is a dramatic high-altitude hot spring in the Yonezawa area of Yamagata Prefecture, one of the celebrated Yonezawa Eight Hot Springs cluster, situated at approximately 1,300 meters elevation in the crater remnants of an ancient volcanic eruption on the slopes of the Dainichi-dake mountain near the border with Fukushima Prefecture, operated by the single inn Masugata-ya Ryokan whose membership in the Yonezawa Hachiyukai hot spring association preserves the exclusive hot spring heritage of this mountain cluster. Ubayu, whose name combines uba meaning old woman or wet nurse with yu meaning hot water, occupies one of the most dramatically situated positions among the Yonezawa Eight Hot Springs, perched at high altitude where the surrounding volcanic terrain, remote mountain access, and the bicarbonate and naturally carbonated mineral waters create an experience of total immersion in the primeval volcanic landscape of the Ou Mountain highlands. The remote alpine setting, the geological drama of the ancient volcanic crater, and the distinctive mineral character of the spring's effervescent waters make Ubayu Onsen one of the most adventurous and memorable thermal bathing destinations in the celebrated Yonezawa mountain hot spring tradition.