The idea that the Great Wall of China can be seen from space has been around since at least 1938 and is still popular today. It certainly seems plausible that such a large, linear structure would stand out from the surrounding landscape, but it’s actually not true.
Alan Bean, the fourth man to walk on the moon, said in 1969
“The only thing you can see from the moon is a beautiful sphere, mostly white, some blue and patches of yellow, and every once in a while some green vegetation. No man-made object is visible at this scale.”
But if you can’t see the Wall from the moon, how about somewhere closer to Earth? The International Space Station (ISS) maintains a low earth orbit of between 330-435 km above our planet’s surface.