Having recently been to (and hated) Las Vegas, I found it fascinating to read this article about a hidden city of homeless living in a network of tunnels beneath the city, including right under the strip.  The scenes described sound like something from a post-apocalyptic film:

There’s a lot of older people, senior citizens, people in their 60s, war veterans, people who have cancer and AIDS. It’s not a very healthy environment down there – just very enclosed and wet

Above ground Vegas struck me as a horrible, bleak place hiding under a very thin surface veneer of glamour and excitement.  It seems fitting somehow that the city literally hides such a dark and hopeless world below its streets.