The Great Wall we talk about today refers to the one in northern China, the construction of which started in the Qin Dynasty (221-206 B.C.). It runs for over 5,000 km, from Lintao in Gansu Province in the west to eastern Liaoning Province in the east. It also refers to the over-10,000-km Han Dynasty (206 B.C.-220 A.D.) Great Wall, which extends westward along the Silk Road, passing Jiuquan, Dunhuang and Lop Nur. The Great Wall also includes the part built in the Ming Dynasty some six centuries ago. The Great Wall has been regarded as a part of the world's cultural heritage for its long history and its gigantic length.
