The Grand Canyon is one of those few things in the world that lives up to its hype. It's a breathtaking, astonishing site, and the National Park Service has done a good job of keeping the area clean and natural (no mini-golf or Wal-Marts!), with signature WPA-era stone and timber architecture for the park service center. I've been there three times and would go back again in a heartbeat.

Recommended: stay in Flagstaff, and stop in on Wupatki National Monument and the Painted Desert areas on your way up to the Canyon. This whole area is peaceful and astonishingly beautiful. One unexpected thing that stays with me is the sound of the wind in the pines that flank the canyon. You'll probably also see chipmunks if you sit still.