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
Great Wall of China natural defensive barriers such as hills and rivers. Another archaeological survey found that the entire wall with all of its branches measures out to be . Today, the Great Wall is generally recognized as one of the most impressive architectural feats in history. The collection of fortifications known as the Great Wall of China has historically had a number of different names in both Chinese and English. In Chinese histories, the term "Long Wall(s)" (長城, "changcheng") appears in Sima Qian's "Records of the Grand Historian", where it referred both to the separate great walls built between and north of the