What to know
Mount Aso (Asosan) is a massive active volcano in central Kyushu. Its caldera, formed by colossal eruptions long ago, spans over 100 kilometers in circumference, making it one of the largest in the world. The caldera is ringed by a circular rim and contains several rural towns and extensive rice paddies.
At the heart of the caldera rise the volcano's active peaks. Tourists can access and view the main crater, though it occasionally closes due to high volcanic gas levels or activity. Horses and cows graze on the grassy slopes of the volcanic peaks, creating scenic pastoral landscapes.
