Great Wall of China the optics much better, rendering photographic evidence irrelevant to the issue of whether it is visible to the naked eye. Great Wall of China 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. Several walls were being built as early as the 7th century BC; these, later joined together and
History of the Great Wall of China that the Great Wall traversed, the sparse populations of these areas, and the frigid winter climate. Although the walls were rammed earth, so the bulk of the building material could be found "in situ", transportation of additional supplies and labour remained difficult for the reasons named above. The sinologist Derk Bodde posits in "The Cambridge History of China" that "for every man whom Meng Tian could put to work at the scene of actual construction, dozens must have been needed to build approaching roads and to transport supplies." This is supported by the Han dynasty statesman Zhufu Yan's description of