Shanhaiguan (also known as Shaoguan, Shaoguan, Linyiguan), located 15 kilometers northeast of Qinhuangdao City, Hebei Province, because it is surrounded by mountains and the sea, it is known as Shanhaiguan. National AAAAA-level tourist attractions, the first batch of key cultural relics protection units in the country, is one of the northeast pass of the Ming Great Wall, known as the "one of the three wonders" of the Great Wall of China, "the first pass in the world", "the throat of the border county, the guarantee of the Beijing teacher". Shanhaiguan City has a circumference of 4727 meters, a city height of 14 meters, and a thickness of 7 meters. Fourteen years (1381) of Ming Hongwu built a city gate to set up a guard. Shanhaiguan has four main gates, a variety of defensive buildings. Including the "world's first gate" arrow building, Jingbian building, pastoral building, Linyi building, Yucheng and the 1350-meter extension of the Ming Dynasty plain Great Wall and other landscapes.