Aira Caldera

is a gigantic volcanic caldera in the south of the island of Kyushu, Japan. The caldera was created by a massive eruption, approximately 22,000 years ago. Eruption of voluminous pyroclastic flows accompanied the formation of the 17 × 23 km-wide Aira caldera. Together with a large pumice fall, these amounted to approximately 400 km³ of tephra (VEI 7).