Cadillac Ranch is a public art installation involving 10 vintage Cadillacs. It was created in 1974 by members of the art group Ant Farm.
Since its beginning the car colours have gone through multiple evolutions. White for a TV commercial, then pink because of a founding member's wife's birthday, and again all 10 cars were painted flat black to mark the passing of Ant Farm artist Doug Michels. In 2012 they were painted rainbow colors to commemorate gay pride day. However most of the time you'll find the cars covered in graffiti.
Photos (except first one) by http://www.tripodgirl.com