Mount Aso Mount Aso (Aso-san), is also known as Aso Volcano and in this sense is the largest active volcano in Japan, and is among the largest in the world. Common use relates often only to the somma volcano in the centre of the Aso Caldera. It stands in

Mount Aso Mount Aso (Aso-san), is also known as Aso Volcano and in this sense is the largest active volcano in Japan, and is among the largest in the world. Common use relates often only to the somma volcano in the centre of the Aso Caldera. It stands in Aso Kujū National Park in Kumamoto Prefecture, on the island of Kyushu. Its tallest peak, Takadake, is 1,592 meters (5,223 ft) above sea level. Mount Aso is in a fairly large caldera (25 kilometers (16 miles) north-south and 18 km (11 mi) east-west) with a circumference of around 120 km (75 mi), although sources vary on the exact distance.