O-Spa

O-Spa is a 24-hour day-use bathhouse in Otaru's port district, a short walk from the ferry terminal. Its onsen water is drawn up from deep underground and comes out clear and distinctly salty, said to keep you warm well after you towel off. The indoor bath sits under a skylight and adds a bubble bath, a waterfall bath (utaseyu, 打たせ湯) and an electric bath, while the outdoor rotenburo (露天風呂) carries a trace of sea air off the harbor. There is a sauna with rounds of rouryu (ロウリュ) and a separate ganbanyoku (岩盤浴) hot stone room heated with Tenshoseki (天照石) mineral stone, charged on top of admission. Upstairs, a restaurant serves local dishes like ankake yakisoba and zangi fried chicken alongside draft beer, and a convenience store sits right in the building for late-night runs. The second-floor hall with reclining chairs stays open around the clock, with blankets to rent for anyone settling in until morning, and it is a regular stop for ferry passengers and touring motorcyclists washing off a long day on the road before sleeping over in their cars.