I read an article just prior to my trip to China and YES it is the only man made structure visable from outter space! Being a "wonder of the world" is a definate discription......how did they do that 2000 years ago? Was what I wondered when I stood on the wall and looked at the vastness of it all!

You only can see it, less than 1,000 miles from the surface of the Earth.

yes you can actually see it from space it is that amazing and large