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 bc; 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 bc by Qin Shihuang, 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.
