雁门关
The Jiayu Pass, located in Gansu province, is the western terminus of the Ming Great Wall. From Jiayu Pass the wall travels discontinuously down the Hexi Corridor and into the deserts of Ningxia, where it enters the western edge of the Yellow River loop at Yinchuan. Here the first major walls erected during the Ming dynasty cut through the Ordos Desert to the eastern edge of the Yellow River loop. There at Piantou Pass "Piāntóuguān") in Xinzhou, Shanxi province, the Great Wall splits in two with the "Outer Great Wall" "Wài Chǎngchéng") extending along the Inner Mongolia border with Shanxi into Hebei province, and the "Inner Great Wall" "Nèi Chǎngchéng") running southeast from Piantou Pass for some , passing through important passes like the Pingxing Pass and Yanmen Pass before joining the Outer Great Wall at Sihaiye in Beijing's Yanqing County.