Great Wall of China China Postcard

The Great Wall of China is a series of fortifications built along the northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups. Several walls were built from as early as the 7th century BC, with later fortifications built over centuries, the most well-known being the parts of the wall built by the Ming dynasty (1368–1644). Aside from defence, other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade, and the control of immigration and emigration. The Great Wall is a series of fortifications made of stone, brick, tamped earth, and other materials. It stretches from Shanhaiguan near the Bohai Sea in the east to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. The total length of the Great Wall is about 21,196 kilometres.