Gozu Onsen-go

On the Sea of Japan coast at Murakami in northern Niigata, Senami Onsen was discovered in 1904 when oil prospectors struck near-boiling water instead of crude. Its 95 °C sodium-chloride springs face straight out to sea, famous for sunsets sinking into the water beside the open-air baths.

A hamlet on the Tadami River in Oku-Aizu with one bathhouse and one minshuku, sharing a 38 °C spring so charged with dissolved carbon dioxide that it ranks among the most carbonated in Japan — tea-brown, faintly salty, lukewarm enough to sit in for an hour, and drunk as well as bathed in. A second spring rises cold a few minutes away: a well of natural sparkling water that Meiji-era traders shipped to Europe and that is still bottled today.