Aira Caldera

The Aira Caldera in southern Kyushu was formed roughly 22,000 years ago by one of the most powerful volcanic eruptions in recent geological history, blanketing much of southern Kyushu in thick layers of pyroclastic material. The resulting basin spans approximately 17 by 23 kilometres and today cradles Kagoshima Bay at its centre, with the still-active Sakurajima volcano rising from the caldera floor as a peninsula — regularly emitting ash columns visible for kilometres around. Trails along the caldera rim reward hikers with sweeping views across the entire volcanic structure and out toward the Pacific, making it one of the most dramatic geological landscapes in Japan.