Jiayu Pass, also called "China's No. 1 Pass", is located in the middle of the narrowest valley which is five kilometers to the west of Jiayuguan city in Gansu province. The walls on both sides of the pass traverse the desert before connecting Xuanbi (literally meaning "Suspended") Great Wall in Heishan Mount on the north and China's No. 1 Pier on the south.

Jiayu Pass is the gateway to the westernmost end of the Ming Dynasty Great Wall, and was historically known as the throat of Hexi area. Thanks to its strategically-important location and grand buildings, Jiayu Pass is nicknamed "Key of the Border". Serving as an important transportation hub on the ancient Silk Road, Jiayu Pass is one of the Three Wonders of the Chinese Great Walls, along with Shanhai Pass in east China and Zhenbei Terrace in central China.

With its construction beginning in 1372 (the fifth year of the Hongwu Period in the Ming Dynasty), Jiayu Pass consists of the inner city, the outer city, the enclosure city, the urn city, the moats, as well as the northern and southern wings, stretching 60 kilometers in total. Jiayu Pass is a world cultural heritage, a national 5A tourist attraction, a key cultural relics unit under national protection, and a national patriotism education demonstrative base.

Built west-facing in a ladder-shaped layout, the pass has a perimeter of 1,107 meters and covers 84,554 sq m. Its inner city is the main part and center of the pass, which also follows a ladder-shaped layout with a 223.5-meter-long east wall, a 224.9-meter-long west wall, a 180.2-meter-long south wall, and a 178.2-meter-long north wall.