Allow me to introduce one of the most well known urban decay landmarks in California. Alcatraz. I tried to take pictures of decay, rather than usual "look, that's me in Al Capone cell!". Some of them are color, others are B&W. It's a pity, most of the structures are fenced off "for your own safety".
I put a couple under a cut, and the rest are here: Alcatraz
Warden House (what's left of it)