Actually, it’s almost 9000km long. Except that in Chinese the number that stands for “a whole heck of a lot” is “ten thousand” and ten thousand li (one of which is officially, as of now, 0.5km) basically means “really freakin’ long”. Therefore the Great Wall of China, the Ten Thousand Li Fortress, is actually an understatement. Not a common thing in Chinese names for awesome things.

So… when they were building the Great Wall of China it may have actually been the first time when humanity built something that exceeded the imagination of language, proving for the first time that engineering majors (or at least emperors with ten thousand slaves) are superior to liberal arts scholars.