Utopia Warakuen Shiriuchi Onsen Inn

Said to be the oldest hot spring in Hokkaido, with records going back to 1247. The inn runs three baths: an upper bath with soft, skin-smoothing water; a lower bath rich in iron, traditionally used to treat burns; and an open-air rotenburo (露天風呂) that can be used privately. The spring is a sodium chloride-bicarbonate type. The building is unassuming, but the water has a long local reputation.