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The Great Wall was built by ancient Chinese people including peasants, soldiers and prisoners. They built it by piling up bricks and stones with cement on the mountains. They built it to protect the land and people to the south of the wall from being attacked by the northern nomadic tribes. The wall starts from Hushan in Liaoning and ends at Jiayuguan in Gansu. The walls can be seen today, but many sections are eroded badly beyond of recognization. It took over 2,000 years to build the wall from Spring and Autumn Period (770 BC - 476 BC) to Ming Dynasty (1368 - 1644).