Yanmen Pass is an important part of the Great Wall of World Cultural Heritage and a national key cultural relics protection unit. It is the ancient pass with the longest history, the most frequent battles, the highest visibility and the widest influence. It is known as the “The Steepest and Most Dangerous Pass in China”. It is located in Yanmen Mountain, about 20 kilometers north of Daixian County, Xinzhou City, Shanxi Province, China. It is an important pass on the Great Wall. It is known as “danger” and is known as “The Steepest and Most Dangerous Pass in China”. “Lead”. Together with Ningwu Pass and Partial Pass, it is called “Outer Three Passes”.