Great Wall of China 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 made bigger and stronger, are collectively referred to as the Great Wall. Especially famous is the wall built in 220–206
Great Wall of China a press release a week later, they acknowledged that the "Great Wall" in the picture was actually a river. Leroy Chiao, a Chinese-American astronaut, took a photograph from the International Space Station that shows the wall. It was so indistinct that the photographer was not certain he had actually captured it. Based on the photograph, the "China Daily" later reported that the Great Wall can be seen from 'space' with the naked eye, under favorable viewing conditions, if one knows exactly where to look. However, the resolution of a camera can be much higher than the human visual system, and