Kanbayashi Onsen Fudoson no Yu Onyado Kotobuki

Onyado Kotobuki is a small six-room ryokan in Kanbayashi Onsen, right at the trailhead into Jigokudani Yaenkoen, where the snow monkeys are. It has two baths, Momiji-no-yu and Shakunage-no-yu, named for the maple and rhododendron that color the forest view from their rock outdoor pools; each pairs an indoor bath with the rotenburo, and both run on kakenagashi spring water, clear and mild on the skin. Men's and women's sides swap by the day, so it's worth checking before you go in. Rooms are plain tatami with a lounge and fireplace downstairs, and cold spring water is kept in the room fridge for drinking after a soak. It's a quiet, family-run place, the kind where you can easily end up with the bath to yourself.