The Great Wall spans more than two thousand years and traverses 5,000 kilometers. The Great Wall, like the Pyramids of Egypt, the Taj Mahal in India and the Hanging Garden of Babylon, is one of the great wonders of the world.Starting out in the east on the banks of the Yalu River in Liaoning Province, the Wall stretches westwards for 12,700 kilometers to Jiayuguan in the Gobi desert, thus known as the Ten Thousand Li Wall in China. The Wall climbs up and down, twists and turns along the ridges of the Yanshan and Yinshan Mountain Chains through five provinces--Liaoning, Hebei, Shanxi, Shaanxi, and Gansu--and two autonomous regions--Ningxia and Inner Mongolia, binding the northern China together.As a cultural heritage, the Wall belongs not only to China but to the world. The Venice charter says: 'Historical and cultural architecture not only includes the individual architectural works, but also the urban or rural environment that witnessed certain civilizations, significant social developments or historical events.' The Great Wall is the largest of such historical and cultural architecture, and that is why it continues to be so attractive to people all over the world. In 1987, the Wall was listed by UNESCO as a world cultural heritage site.