Ibusuki volcano is a group of calderas, central cones and maars at the southern tip of Kyushu Island, Japan. Although the last eruption dates back to the 9th century, it is an active volcano. It contains the 4.5-km-wide Ikeda-ko caldera, which formed about 4600 years ago, and the andesitic Kaimon-dake stratovolcano, the most prominent feature of the volcano. Kaimon-dake contains a lava dome at the summit. The Ibusuku volcano has been very active during the past 10,000 years. Since about 2650 years ago, all activity has taken place from Kaimon-dake, the last one in the 9th century.

The large 20 km wide Pleistocene Ata caldera was originally believed to belong to the Ibusuki volcano, but it is probably related to a different magmatic system. It underlies Kagoshima Bay.

Ibusuki Hot Springs

There are many (over 800) hot springs in Ibusuki (such as Surigahama, Kawarayu, and Yajigayu Hot Springs) concentrated along the 5km coast on the southeastern tip of the Satsuma Peninsula. The geothermal activity is related to faults in and around the Ata caldera, permitting heated water to circulate up to the surface.

The springs are famous for "sand bathing" on a beach, heated by a hot spring.