What is the total length of the Great Wall of China, according to an official 2012 survey?

The total length of the Great Wall of China is 21,196 kilometres, according to an official 2012 survey. This figure includes walls, trenches, natural barriers, and other defensive features built across successive Chinese states and dynasties.

The best-known sections were constructed or strengthened during the Ming dynasty, especially from the 14th to the 17th centuries. The wall was not one continuous structure built at one time; earlier walls existed centuries before the Ming period, and many sections used local materials such as rammed earth, brick, and stone.

A common mix-up is the frequently quoted figure of about 8,850 kilometres. That number refers to the Ming-era defensive system measured in a different survey, while 21,196 kilometres covers the wider historical network. The wall was designed mainly to control movement and protect settlements and trade routes, not to form an absolutely impassable barrier. UNESCO added the Great Wall to its World Heritage List in 1987.