Mount Kusatsu-Shirane, Joshin'etsukogen National Park

Mount Kusatsu-Shirane is a 2,160 m active stratovolcano in Kusatsu, Gunma, Japan. It is called Kusatsu Shirane to differentiate it from the Mount Nikkō-Shirane on the other side of Gunma Prefecture. The summit of Kusatsu-Shirane volcano, located immediately north of Asama volcano, consists of a series of overlapping pyroclastic cones and three crater lakes. The largest of these is Yu-gama, an acidic emerald green lake with rafts of yellow sulfur sometimes seen floating on its surface. ()