Yanmenguan Pass Located on the Yanmen Mountain northwest of Dai County, Shanxi province, Yanmenguan Pass is one of the Outer Three Passes (the rest two are Ningwuguan Pass and Pianguan Pass) along the Great Wall.
The pass is located on the summit of a hill accessible only by an ancient trail which winds its way up between cliffs. Originally built in the Tang dynasty (618-907) and rebuilt under the Ming (1368-1644), it was well known for its strategic importance. In 1374 during the Ming dynasty, Ji'an Marquis Lu Heng moved Yanmenguan Pass several kilometers to the north, and built a new pass city at present place. The castle of the Yanmenguan Pass measures 1 kilometer in circumference, with the brick-and-stone wall rising 6 meters. There used to be a gate on the east, west and north. Today, however, people can only see a pair of stone lions, a couple of flag posts and a few stone steles apart from the remains of the arched gates.