Tera-daira, Mafune, Nishi-go Village, Nishishirakawa District, Fukushima Prefecture
Rating
Cost per person
¥5,000
Koshi Onsen, also known as Kashi Onsen, is a secluded hot spring retreat nestled in the Abukuma River's headwaters near Shirakawa, Fukushima Prefecture. The main accommodation is Daikokuya, rebuilt in 2009 with modern facilities. A highlight is the mixed-gender Dai-iwa-buro (Great Rock Bath), accessed via a long staircase and suspension bridge, featuring a large, natural rock formation within the bath. Women have a dedicated bath next to the mixed bath. There are also separate-gender indoor and outdoor baths closer to the main building. The waters are known for their therapeutic qualities, with varying temperatures across the different baths.