Boyoso

This started out as a public lodge on Obama's waterfront and switched to day-use bathing only a few years back, so there's no overnight stay or food service, though bringing your own is fine. The indoor bath is large and plain, and there is an open-air bath as well. There's also a waterfall bath, a jet bath, and a stretch of the bathing area that runs into a small cave, plus a big tatami hall used as a rest area. It's more of a locals' spot than a tourist one, and more than one reviewer says the water itself is the reason to come back.