By way of The Amateur Archaeologist - A new survey has revealed the Great Wall of China to be 21,196 kilometers long. How amazing is that? Consider how long it was previously thought to be:
This was the first time such a figure had been released, as a preliminary survey in 2008 only showed that the Great Wall structures built during the Ming Dynasty (1368-1644) extended more than 8,850 km.
The circumference of the Earth is just over 41,000 km, meaning the Great Wall, if straightened, would extended more than halfway around the world.
Unfortunately, the Wall is not in good shape.
Damage from human activities, such as mining, infrastructure development and profit-driven tourism, have been detected in recent years. Some local residents have taken soil or bricks from the wall, and have planted crops over ruins of it, according to the survey report.
So far, only 8.2 percent of the wall built during the Ming Dynasty remains intact, 74.1 percent is in poor condition, and in some sections, only its foundation remains, according to the report.
A large amount of the wall has collapsed. "The saving and preserving of the Great Wall's relics should not be delayed," the report stresses.
This is why you are not actually able to see the Great Wall from space; most of it has either been destroyed or is too overgrown with vegetation.