Regarding Shanhaiguan, located in Qinhuangdao, the deepest impression is that at the time of the late Ming and early Qing dynasties, Wu Sangui rushed to the crown and became angry, and opened the Shanhaiguan to put the gold into the customs. This is a very long and strong place that has been regarded as the starting point of the eastern end of the Ming Great Wall. The walls are towering, the bricks are heavy, and there are many defenses. If it is not the active switch, it is necessary to overcome. The second pass is no easy task. Shanhaiguan's "the first pass in the world" is also very powerful. It was written by the Xianguan of the Ming Dynasty in the eight years of the Ming Dynasty. Shanhaiguan is an important barrier to the east of Beijing. It is an important arch of the security of the Ming Dynasty.