The City Wall is the best-preserved of all such ancient city architecture in China; it is also the most integrated and the largest city wall in the world. It was built on the ruins of the imperial city of the Tang Dynasty for defence so was very robust.

The city wall is 12 metres in height. It is 12 to 14 metres wide across the top, 15 to 18 metres thick at the bottom, and 13.7 kilometres in length.