La楽リゾートホテル グリーングリーン

The hotel's bath hall, called Jabun (じゃぶ〜ん), has a wide outdoor bath that wraps around a view of Sakunami's hills and shifts with the seasons, plus an indoor bath and a low-temperature bakuhanseki (麦飯石) stone sauna. There's a cave-styled corner too (dokutsuburo, 洞窟風呂), and the women's bath, Tenku no Yu (天空の湯), opens straight up to the sky. A private bath can be booked at the front desk on the day of your stay. The water is a mild spring that leaves skin feeling smooth, which is why it's known locally as Bijin-zukuri no Yu (美人づくりの湯), the beauty-making bath. Green Green is a big, 17-story resort built around indoor amusement as much as the bath: bowling, karaoke rooms, an arcade, an indoor pool, and rentals for mahjong, go, and shogi. Recent reviewers describe the place as a Showa-era time capsule, retro and a little worn in spots but kept clean, with a mazelike layout that rewards exploring. It's less a quiet ryokan and more a full resort built around the onsen.