Nakabusa Hot Spring

A remote mountain inn near the Azusa River trailhead with an unusually large collection of baths, around 17 in total, indoors and out, all fed by 29 registered springs, most running naturally hot at over 90°C and cooled without chemicals or recirculation. The simple sulfur water is alkaline enough to leave skin noticeably smooth. Highlights include a waterfall bath (Shirataki no Yu), a bath inside hollowed tree roots, and a moongazing rotenburo (露天風呂) at the highest point of the grounds.