Last Sunday I visited Meteor Crater for the first time in just over a decade. The crater (once called Coon Mountain Butte), also known as Barringer Crater, is the first confirmed asteroid impact crater on Earth.
For a long time many thought that the site was a volcanic feature. Likely the presence of the San Francisco volcanic field (on the horizon in the photo below), northwest of the crater, clouded the judgement of the early geologists, but the clues as to its origin are everywhere.
There's a nice museum that's well worth looking at. I was especially happy to see so much devoted to Eugene Shoemaker, the man who proved that the crater was created by an asteroid impact. If you haven't read it, I highly recommend David Levy's biography of him, Shoemaker by Levy and if you want to read about the crater I suggest tracking down the classic book by H.H. Nininger Arizona's Meteorite Crater.
Here is one of the panoramas I shot of the crater: