Yanmenguan Pass, which is also called Yanmensai or Xijing Pass, is located at the Ridge of Gouzhu Mountain, south out of Datong city in Shanxi Province. Yanmenguan Pass is the first of the Outer Three Passes (the rest two are Ningwuguan Pass and Pianguan Pass) through the inner line of the Great Wall in Shanxi. Now it is well preserved as a precious ancient military relic.

Originally built in the Tang Dynasty (AD 618 AD - 907 AD) the Pass Gate of Yanmen Guan was rebuilt and extended several kilometers to the north in 1374 AD during the Ming Dynasty (1368 AD - 1644 AD). Throughout history it was known as "one of the nine strategic forts in China" since the Warring States period (475-221 B.C.).

Yanmenguan Pass earned its name Wild Goose Pass (Yan means goose in Chinese) for its precipitous location. Yanmenguan Pass cuts through the crest of Mount Gouzhu, which is so high that it is said to be a challenge even to the wings of a wild goose. At Yanmenguan Pass, a six-meter-tall wall guards the entrance to a castle Guang Wu Fortress, which functions as a town with the brick-and-stone wall rising up to an impressive 6 meters high. There used to be three gates at Yanmenguan Pass: the small north gate, west gate and east gate. However, today, only a pair of stone lions, a couple of flag posts and a few stone steles remained.

The Opening time of Yanmenguan Pass is 08:00-18:00 and the admission fee is RMB 45(free for children under 1.1M).