Introduction to the Yin Yang Stone Archway: There is a stone screen in front of the Yin Yang Stone Archway. The archway and screen were both built in the second year of Tianqi (1622) in the Ming Dynasty. The unicorn relief on the screen, the vast sky above the head, and the rolling sea water under its feet. It can be dry or wet all year round, rain or shine. This is a great wonder of Mengding Mountain.