What did astronaut William Pogue think he saw from the Skylab?

I've been on the wall 3 times; very steep as it goes up and down the hills, and some of the steps are almost completely worn down from so many people walking on it!

And just how long is this longest canal in the world?

One of my bucket list items.

Maybe maybe not! but I guess we'll never know... guess we'll never known!

I've not heard of the great wall of china

I walked some of that wall. It really is something.