How was the great nature of Aso created?
Aso possesses the world’s largest Caldera with 18km west-east and 24 km north-south,
created by 4 times of explosive volcanic activity in the ancient time, 3 million years ago.
Surrounding the caldera is the world’s largest outer mountain, and there are 5 mountains
included Mt. Naka which is still active volcano in the outer mountain.
The 4 times volcanic activities in the ancient time also affected the surrounding area of Aso,
resulting in the formation of the following nature.
Takachiho Gorge, Nabegataki water fall, Harajiri water fall, Keya cave
Dec. 26, 2023