Shirahone Onsen

Shirahone Onsen's hot springs are thought to have been used since the Kamakura period (1185–1333); local accounts describe samurai bathing here while crossing the mountain passes, and by the late Edo period farmers from Matsumoto came to recuperate after the planting and harvest seasons. The water emerges clear but turns milky white within minutes of meeting the air, as calcium and magnesium bicarbonate breaks down and sulfur particles precipitate. The village was originally called Shirafune ('white boat') before being renamed Shirahone ('white bone') after appearing under that name in a Meiji-era novel, a nod to the bone-like calcified deposits that form on the pool rims.