![]() | |||||
| |||||
![]() 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. Several walls were being built
as early as the 7th century BCE; these, later joined together and made
bigger and stronger, are now collectively referred to as the Great Wall. Especially famous is the wall built
220–206 BCE by Qin Shi Huang, the first Emperor of China. Little
of that wall remains. Since then, the Great Wall has on and off been rebuilt,
maintained, and enhanced; the majority of the existing wall is from the Ming Dynasty. 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. Furthermore, the defensive
characteristics of the Great Wall were enhanced by the construction of watch
towers, troop barracks, garrison stations, signaling capabilities through the
means of smoke or fire, and the fact that the path of the Great Wall also
served as a transportation corridor. The Great Wall stretches from Dandong in the east, to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,850 km (5,500 mi). This is made up of 6,259 km (3,889 mi) sections of actual wall, 359 km (223 mi) of trenches and 2,232 km (1,387 mi) of natural defensive barriers such as hills and rivers. Another archaeological survey found that the entire wall with all of its branches measure out to be 21,196 km (13,171 mi). |