Otani Sanso

Otani Sanso is a large hot-spring ryokan in Nagato Yumoto, built along the Otozure River in Yamaguchi. 21 of its rooms come with their own outdoor onsen bath. Two communal baths, Seseragi-no-yu (せせらぎの湯) and Komorebi-no-yu (こもれびの湯), add indoor and outdoor tubs, a sauna and a cold plunge, with the men's and women's sides swapping each morning. The alkaline water is soft and gentle, the kind of spring locals call a bath the whole family can share, from babies to grandparents. The spring has been flowing since 1427, in the Muromachi era, and the ryokan builds its stay around that sense of place: seasonal kaiseki cooked from local ingredients, an astronomy dome for stargazing, and a foot bath tucked into the garden by the lobby.