It is commonly claimed that the
Great Wall of China is the only human-made object visible from the Moon. This is false. None of the
Apollo astronauts reported seeing
any specific human-made object from the Moon, and even Earth-orbiting astronauts can barely see it. City lights, however, are easily visible on the night side of Earth from orbit.
http://en.wikipedia.org/wiki/List_of_common_misconceptions#cite_note-119 Shuttle astronaut
Jay Apt has been quoted as saying that "the Great Wall is almost invisible from only 180 miles (290 km) up."
http://en.wikipedia.org/wiki/List_of_common_misconceptions#cite_note-120 ISS commander
Chris Hadfield attempted to find it from space, but said that it was "hard as it's narrow and dun-colored