The idea that the only man-made structure that can be seen from outer space is the Great Wall of China? That's a myth. In fact, from the moon, one can also clearly see New Jersey trash dumps and (if the weather is clear) the words "NORTH AMERICA."
However, one thing that is no longer debatable is that there are LOTS of man-made monuments—some deliberately so, some accidental—that can be seen from a space satellite. Whether the object is buried underground or partially under the ocean, space satellites can snap a pic.
Check out some of the more impressive man-made landmarks below