Lake-filled Mikurigaike crater is part of Tateyama, an eroded stratovolcano on a plateau surrounded by the granite and gneiss peaks of the North Japan Alps. Formation of a 4-km-wide caldera was followed by Pleistocene eruptions of lava and pyroclastics forming a plateau that was later eroded by the Yukawa river. Holocene eruptions have been restricted to small phreatic explosions that formed craters such as the one seen here. Photo by Ichio Moriya, 1992 (Kanazawa University).