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
Defense of the Great Wall Defense of the Great Wall The Defense of the Great Wall () (January 1 – May 31, 1933) was a campaign between the armies of Republic of China and Empire of Japan, which took place before the Second Sino-Japanese War officially commenced in 1937. It is known in Japanese as and in many English sources as the First Battle of Hopei. During this campaign, Japan successfully captured the Inner Mongolian province of Rehe from the Chinese warlord Zhang Xueliang and annexed it to the new state of Manchukuo, whose southern frontier was thus extended to the Great Wall of China.