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 structure. The existence of a colossal wall in Asia had circulated in the Middle East and the West even before the first Europeans arrived in China by sea. The late antiquity historian Ammianus Marcellinus (330?395?) mentioned "summits of lofty walls" enclosing the land of Seres, the country that the Romans believed to be at the eastern end of the Silk Road. In legend, the tribes of Gog and Magog were said to have been locked out by Alexander the Great with walls of steel. Later Arab writers and travellers, such as Rashid-al-Din Hamadani (12481318) and Ibn Battuta (13041377), would erroneously