According to China's State Administration of Cultural Relics, the total length of the Great Wall of China building in different dynasties is 13,170.69 miles (21,196.18 kilometers).
There are three groups of people who built the wall: soldiers, common people and criminals, not the emperors of each dynasty including Qin Shihuang himself. During the Qin Dynasty (221 - 207 BC), 20% of the country’s population was forced to build it. Many people died during its construction, due to the heavy work, a short time deadline and difficult conditions.
Construction started in the Spring and Autumn Period (770 - 476 BC), and lasted until the Ming Dynasty (1368-1644). The purpose of building it was to protect people and territory from invasion.
Find more facts about the Great Wall at Travel China Guide.
Speaking of the Great Wall, Matt Damon Battles Clusters of Monsters in the movie ‘The Great Wall’.
Snarling digital monsters, a glowering Matt Damon and battalions of unfaltering Chinese warriors mix it up in “The Great Wall,” a painless, overstuffed spectacle that works overtime as a testament to China’s might.
Set once upon a time, the movie spins a legend that never was: Every 60 years, slavering creatures emerge from beyond to sharpen their teeth on human bones and stuff their bellies on meat. The whole thing plays out as if it had been thought up by someone who, while watching “Game of Thrones” and smoking a bowl, started riffing on walls, China and production money. Read more of the movie review at The New York Times.