The Gubeikou Great Wall. Gubeikou is located in the north of Miyun County, Beijing. It was the communication gorge of south and north in the Yan Mountain Chain. Its former name was ‘the North Tiger Pass’, since it lies to the north of the Crouching Tiger Mountain that is seated to the southwest of the pass. In the Ming Dynasty Gubeikou was a main access for the Mongolian tribes to paying tributes to the Court. The Court’s awards in return also passed from the pass. The pass had crucial military importance, having the Twisting Dragon Mountain and the Crouching Tiger Mountain on the north, the Qingfeng and the Diecui mountain ranges on the south, and the Chao River passing through from north to south. The chief rampart of the Great Wall joins the Twisting Dragon Mountain and the Crouching Tiger Mountain together, and thus the three form a marvelous barrier.
The pass was first built in the Northern Qi Dynasty. In the Jin Dynasty the name Gubeikou was changed into ‘the Iron gate pass’. When the Ming Dynasty overthrew the Yuan Dynasty and began the construction of the Great Wall, it was one of the first built passes by Xu Da. In lunar August, 1550, Anda, the leader of a Mongolian Dada tribe, commanded his cavalry to go down the Chao River and conquered Gubeikou, and surrounded Beijing for three days and nights, looting and robbing outside the city. It was called in history ‘the Geng Xu Event’. After that the Court intensified the construction of the section. The strong and grand Gubeikou Great Wall was a complete defense system, among which multiple pass cities were connected and continuous watch towers could coordinate effectively with one another. The pass city was called ‘Yingcheng’ (the encampment city), seated upon the summit, ranging from the Eastern Pass Gate in the east to the Chao River in the west. The perimeter of the city is 2 kilometers with three city gates to the east, north and south respectively.