Shanhaiguan is located in the northeast of Qinhuangdao 15km, which is the starting point of the eastern end of the Great Wall in Wan Li. In the 14th year of Hongwu in Ming Dynasty (138 1), General Xu Da built the Great Wall here and set up a guard. Named after being locked between mountains and seas. Shanhaiguan is bordered by Yanshan Mountain in the north and Bohai Sea in the south. It is the throat of Northeast China and North China, and it is a battleground for military strategists in history. As the saying goes, "The lock and key of the two capitals are unparalleled, and the Great Wall of Wan Li is the first pass". The Ming Great Wall extends northward from the old dragon head on the south bank of Shanhaiguan and winds across the top of Shanhaiguan. There are four gates in Shanhaiguan near the Great Wall in the east, the East Gate of Zhendong in the east, which is the first gate in the world, the Yingen Gate in the west, the Wangyangmen in the south and Weiyuan Gate in the north. There are towers on every gate, bell and drum towers in the center and moats around the city.