Isawa Onsen Minamoto Ryokan

The bath to know here is outdoors and tinted with red wine, a lightly scented soak that's become the inn's signature and a hit with kids. There's also a plain indoor bath open around the clock, and a private bath you can reserve for time alone. The water is alkaline and soft on the skin, and even committed onsen fans rate it well. Minamoto Ryokan itself is a small, old-school building from the Showa era, worn in a lived-in way rather than renovated over, with rooms refreshed inside that retro shell. Dinner is built around duck, sukiyaki to hot pot, in portions generous enough that reviewers recommend checking photos before ordering.