Wall stretching across northern China from Hebei Province in the north-east through Shanxi, Shaanxi and Ningxia provinces to Gansu Province in the west (see fig.). Running through inhospitable mountains and deserts, with numerous offshoots and parallel structures, it is one of the most spectacular feats of engineering in the history of the world. Although it was built primarily as a defence against the Central Asian nomads, it also provided a relatively efficient thoroughfare for the movement of troops, horses and supplies across difficult terrain. According to the traditional Chinese view, the wall also created a spiritual and physical barrier between the ‘superior’ and sedentary culture of China and the ‘inferior’ culture of its nomadic neighbours.
Defensive walls, such as that measuring 7 km at Zhengzhou, Henan, were a feature of Chinese cities from at least the Shang period (c. 1600–c. 1050