Shanhaiguan, also known as Shaoguan, Shaoguan, Linyiguan, is located 15 kilometers northeast of Qinhuangdao City, Hebei Province. It is one of the northeast passes of the Ming Great Wall. It was considered as the starting point of the eastern end of the Ming Great Wall before 1990. It has been known as the "one of the three wonders" of the Great Wall of China (East Youshan Customs, Zhongzhen Beitai, The west has Jiayuguan), "the world's first customs", "the throat of the border county, the guarantee of the Beijing teacher", and the Jiayuguan thousands of miles away echo, famous in the world. Ming Hongwu 14 years (1381) built a city to establish a guard, because it is surrounded by mountains and sea, so called Shanhaiguan. Shanhaiguan City is about 4 kilometers long, connected to the Great Wall, with the city as the gate, the city is 14 meters high, 7 meters thick, there are four main city gates, a variety of defensive buildings. Including the "world's first gate" arrow building, Jingbian building, Muying building, Linyi building, Yucheng and the 1350-meter extension of the Ming Dynasty plain Great Wall and other landscapes.