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 feature prominently. The French philosopher Voltaire (16941774), for example, frequently wrote about the Great Wall, although his feelings towards it oscillate between unreserved admiration and condemnation of it as a "monument to fear". The Macartney Embassy of 1793 passed through the Great Wall at Gubeikou on the way to see the Qianlong Emperor in Chengde, who was there for the annual imperial hunt. One of the embassy's members, John Barrow, later founder of the Royal Geographical Society, spuriously calculated that the amount of stone in the Wall was equivalent to "all the dwelling houses of England and Scotland" and would