The Great Wall of China stretches 10,000 miles along an arc that delineates the southern edge of Inner Mongolia.
 He wrote that the wall is "sixty days' travel" from Zeitun (modern Quanzhou) in his travelogue Gift to Those Who Contemplate the Wonders of Cities and the Marvels of Travelling
 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

