Decrepit buildings turned Masterpeices

Not too long ago I was in New York City walking around being captivated not just by the food but by the amazing graffiti. It ranged from the standard tagging, writing a name, to giant murals that depicted what it was like in that neighborhood. Some were political and some were just for fun, but much of it was impressive. Now I know that graffiti done on an occupied building is vandalism but there is a fantastic site that has been monitoring all of this. Graffiti Archeology keeps timelines of walls and you can go back years and see the changes that artists have made over that time.