Can you see the Great Wall of China from space?

No. The wall is only 5 to 8 metres wide at the base and roughly matches the colour of the surrounding land, so the naked eye cannot pick it out from orbit. China's first astronaut, Yang Liwei, said in 2003 that he could not see it. From the International Space Station, with a camera and good light, it has been photographed, but so have motorways and airports, which are wider.

Source: NASA (2005); Yang Liwei statement (2003)