Great Wall Even Greater than Thought
June 11, 2012
The Great Wall of China is more than twice as long as originally believed, China’s State Administration of Cultural Heritage (SACH) recently announced. According to the first definitive archaeological survey of the ancient structure, the wall is 13,170.6956 miles (21,196.18 kilometers) long. A preliminary SACH estimate released in 2009 set the length at 5,500 miles (8,850 kilometers). The survey, begun in 2007, mapped every trace of the wall across 15 Chinese provinces. In his report, SACH deputy chief Tongo Mingkang noted that some 43,700 heritage sites were identified during the survey, “including stretches of the wall, defense works and passes, as well as other related Great Wall facilities and ruins.”

The Great Wall of China stretches about 13,170 miles (21,000 kilometers) across northern China. It was originally built to keep out invaders. (© Susan Zheng from Peter Arnold, Inc.)
The Great Wall–originally contracted of stone, bricks, and packed earth–is the world’s largest structure constructed by people. Begun some 2,500 years ago, it was designed to protect China’s northern border from marauding tribes from what is now Mongolia. Although work continued on the wall for centuries, the majority of the existing structure was reconstructed during the Ming Dynasty (1368-1644). Only 8.2 percent of the Ming wall remains intact. The survey crew found that in many places the wall has collapsed; in other sections, only the foundations remain.
UNESCO listed the Great Wall as a world heritage site in 1987. UNESCO is a specialized agency of the United Nations (UN) that fosters peace and security through cooperation in the areas of education, science, and culture.