Kumanoyu Hotel

The signature here is the water itself: it runs a clear jade green, carries a real sulfur smell, and leaves your skin feeling smooth rather than dry. There are two bathhouses, each with a hinoki (cypress) indoor bath and a smaller outdoor bath, and they swap between men's and women's use every day. The outdoor baths run noticeably milder than the indoor ones, so they're the spot for a long soak. Kumanoyu Hotel sits right at the Kumanoyu ski slopes in Shiga Kogen, and the building still has the feel of an old-school ski lodge, worn in rather than renovated away. The onsen's name traces back to a local story of a bear soaking an injured leg in these waters; the spring was later brought to wider attention by the Edo-period scholar Sakuma Shozan and was a favorite of the poet Yosano Akiko.