Great Wall of China? Looks like All of China to me. We have a Great Wall of China downtown. Terrific chow mein, and the egg rolls are pretty tasty too.
I checked that image with a map of the wall and it fairly close. Also, highly unlikely that is a highway, else it would be the largest ever made and located in rural China.
Landmarks 
http://www.googlesightseeing.com/2005/07/21/the-great-wall-of-china/
http://en.wikipedia.org/wiki/Image:Gwc-from-space.jpg
But if you follow the vertical line with Google Earth, it's a road.
Would Nasa be mistaken?