Looked it up. Aso has been around for a long time...
Mount Aso is the largest active volcano in Japan, and is among the largest in the world. It stands in Aso Kujū National Park in Kumamoto Prefecture, on the island of Kyushu. Its peak is 1,592 meters above sea level. Mount Aso has a fairly large caldera with a circumference of around 120 km, although sources vary on the exact distance.
Thank you - largest volcano. Interesting. I didn’t have time to look up, had to do my mountain. :-D