I saw this picture today, not sure you saw it as well, but couldn't resist sharing. It basically shows the existing fence between USA and Mexico. Apparently someone installed some see-saws on the fence so that children on both sides can play together.
I was struck at how this picture in such a small space captures some many differences between these two places. Nobody needs to explain which side is which. One side is orderly, clean, where the people are well dressed. The other side is run-down, dirty, with litter everywhere, stray dogs, folks with minimal clothing, dirty. It's easy to understand the appeal of trying to get over that fence.