Welcome to Cadillac Ranch. It is a famous art sculpture in Amarillo, Texas which consists of what were either older running used or junk Cadillac automobiles from 1949 to 1963, half-buried nose-first in the ground, at an angle corresponding to that of the Great Pyramid of Giza in Egypt. Writing graffiti on or otherwise spray-painting the vehicles is now encouraged, and the vehicles, which have long since lost their original colors, are wildly decorated. It is a really cool thing to see and I think a great idea for people to express themselves in a constructive way. Definitely encourage you to check it out when you are in the area.
Looks like a modern American Stonehenge — but more colorful. Love the pics!