Undercity

I'm utterly fascinated with photos and videos about abandoned and underground places.  I love photos of ghost towns, abandoned hospitals and subterranean places like subways and tunnels.  There's a great video about the exploration of New York City's underworld over on Vimeo called Undercity.  If you haven't seen it yet, do yourself a favor and watch it now (even at its length it's more than worth it):

UNDERCITY from Andrew Wonder on Vimeo.