Onnetō Hot Falls

About

Onnetō Yu-no-Taki is a hot waterfall near Lake Onnetō in Akan Mashu National Park, Hokkaidō, Japan. Water of a temperature of 43 °C (109 °F) descends from a height of 30 m (98 ft). Formerly an onsen, its use as an open-air bath was discontinued after it was discovered that the site and its black mud contains an important deposit of manganese. The Onnetō Hot Falls Manganese Oxide Generation Area was designated a Natural Monument of Japan in 2000.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.