where exactly is the great wall of China? and how long is it?

Hi, it starts from Hushan in Liaoning in the east and ends at Jiayuguan Pass in Gansu in the west, via the nine provinces or cities in northern China, including Liaoning, Hebei, Beijing, Tianjin, Shanxi, Shaanxi, Inner Mongolia, Ningxia and Gansu.
It is 8, 851.8km (5,500mi).

thanks a lot