Sanguankou Great Wall, Ningxia 宁夏三关口长城
Sanguankou is a gap in the Helan Mountains in Yongning County, southwest of Yinchuan, on the border between Ningxia and Alxa Left Banner in Inner Mongolia. In the Chenghua and Jiajing reigns of the Ming, a rammed-earth wall was built on the terraces at the foot of the mountains to guard the road west from the Ningxia Plain; it was one of the four strongpoints of old Yinchuan’s defences.
