China contains the largest portion of the Great Wall of China.
The Great Wall is a vast system of fortifications built, rebuilt, and connected across northern China over many centuries. It was designed mainly to protect settled agricultural regions from raids and military incursions from the north.
The best-known sections date from the Ming dynasty, which ruled from 1368 to 1644. These sections often use brick and stone and include watchtowers, passes, and defensive walls. Earlier walls were frequently made from compacted earth and other local materials.
The wall is not one continuous structure from a single period. Archaeological surveys count many separate walls and defensive works, with total lengths varying according to what is included. Popular claims that it can be seen clearly from the Moon are false. The Great Wall became a UNESCO World Heritage Site in 1987 and remains one of China’s most recognizable historical landmarks.