Hakone Kowakudani Onsen Mizunooto

This hotel draws on two source springs, with sodium chloride water feeding two separate indoor-outdoor bathing halls (large baths with attached rotenburo), used on a men's/women's rotation. In the garden, a small stream runs past three private rotenburo that guests can book for a soak just for themselves or their party, though these have no washing area, only the tub. Some room categories come with their own outdoor bath fed by the same onsen water; others have a plain hot-water tub, so it is worth checking which type you book. The building sits among trees in Kowakudani, one of the small onsen villages inside Hakone, and the common areas lean toward a quiet, low-key mood rather than a grand ryokan atmosphere.