The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe with an eye to expansion. read more
The Great Wall of China was built more than two thousand years ago originally, to defend barbarians called Xiongnu, who might be ancestors of Huns. A few centuries later, during Han dynasty, both sides of the wall were Han's territory, so the wall was not used any more. read more