Jiayuguan, known as the "first Xiongguan in the world",[1] is located in the middle of the narrowest valley 5 kilometers west of Jiayuguan City, Gansu Province. The walls on both sides of Chengguan cross the desert Gobi, the Great Wall of Montenegro in the north, and the first pier in the south. It is the westernmost gate of the Great Wall of Ming Dynasty. Historically known as the throat of Hexi, due to the dangerous terrain, the building is majestic, there is a key to lock the key. Jiayuguan is the traffic fortress of the ancient "Silk Road", one of the three wonders of the Great Wall of China (East there is Shanhaiguan, there is town Beitai, there is Jiayuguan in the west). [2] Jiayuguan was built in Minghongwu five years (1372), composed of the inner city, outer city, Luocheng, Yucheng, Chenghuang and the north and south wings of the Great Wall, the total length of about 60 kilometers. The Great Wall, Duntai, and Fort City are scattered, and the three defense lines of the inner city, the outer city, and the city are overlapping and guarding, forming a defense system of five miles, ten miles, one pier, thirty miles, and one castle.