Kaizu Onsen Chufune no Yu

Chufune no Yu (宙舟の湯) is a large bathing complex with nineteen tubs, indoor and outdoor, fed straight from the spring. Outside there's a rock bath, a tsubo-yu with a falling-water shower, and a box sauna that's rare for the region; inside there are cypress and granite tubs, an electric bath, a jet bath, and a bubble bath, alongside a separate circular source-fed bath called Choju no Yu (長寿の湯). The water itself is the draw: a golden, iron-rich onsen that runs reddish-brown and slightly cloudy in the tub. The two public bathhouses trade sides between men and women each week, so regulars end up trying both. Above the baths it's also a proper place to stay, plain and a bit dated in style, with a restaurant and a karaoke room, feeling more like a lively local spot than a polished resort; it sits in the town where three of the region's big rivers meet.