Mount Aso is a 5,223-foot peak on the island of Kyushu, Japan.
The mountain was once a volcano, but it’s now a caldera, a crater formed when the cone of a volcanic mountain collapses. The caldera of Mount Aso is the largest volcanic Crater on earth, measuring more than 17 miles across. Its total circumference is some 71 miles!
This crater is so large that people live inside it. Three towns and 11 villages, home to thousands of people, are located within the huge volcanic crater!