C127 Four Santonix Caverns

Qilian Mountains is the border mountain system of northeast Qinghai-Tibet Plateau. It is 800 kilometers long in east and west, 200 ~ 400 kilometers wide in south and north, and 4000 ~ 6000 meters above sea level. There are 3306 glaciers, covering an area of about 2062 square kilometers. The terrain was extremely dangerous, and since ancient times