Izumi-so

Izumi-so runs seven different baths: a lie-down open-air bath, a Showa-retro indoor bath, a garden-view rotenburo, and three free reservable private baths, including one built into a small cave called Mogura-buro (もぐら風呂). The two large baths swap between men's and women's use through the day rather than mixed bathing, and a few room types come with their own open-air bath. The water itself is clear and colorless, with a smooth, faintly slippery feel that locals say keeps you warm long after you get out; the inn even recommends it for a baby's first onsen. The ryokan takes its name from the novelist Mushanokoji Saneatsu (武者小路実篤), who was fond of this water. It comes from Izu Nagaoka's founding spring, dug here in the Meiji era before the area later joined with the neighboring Kona hot spring to form today's Izu Nagaoka onsen. The old wooden building still has that retro ryokan feel.