Great Wall of China

The Great Wall's construction began as early as the 7th century BC, when various states built walls for defense. The first emperor of China, Qin Shi Huang, connected and extended these walls in the 3rd century BC to fend off northern nomads.¹ Over the centuries, successive dynasties, especially the Han and Ming, rebuilt and expanded the wall. The most well-preserved sections date from the Ming dynasty (1368–1644), which used bricks and stone for durability.²

The wall includes walls, watchtowers, beacon towers, and garrison stations. It was not a single continuous wall but a network of fortifications. The Ming wall averages 6–7 meters high and 4–5 meters wide, with crenellations for defense.³ Beacon towers used smoke signals by day and fire by night to communicate over long distances.

The Great Wall is a symbol of China's historical strength and perseverance. It has been a UNESCO World Heritage Site since 1987.⁴ It is also a major tourist attraction, with sections like Badaling and Mutianyu near Beijing drawing millions of visitors annually.

Beyond the popular narrative, the wall has many lesser-known facets. For instance, the wall is not visible from the Moon with the naked eye, contrary to a common myth.⁵ Also, the wall's total length was only accurately measured in 2012, revealing it to be over 21,000 km, including natural barriers like rivers and hills.¹ The wall also served as a transportation corridor and facilitated trade, not just defense. Additionally, parts of the wall are made of rammed earth, which has led to erosion and decay in some sections.

Rammed earth

A construction material made by compacting soil, used in early wall sections.

Beacon tower

A tower used to send smoke or fire signals for communication.

Ming dynasty

The last imperial dynasty of China (1368–1644), which built the most famous wall sections.