Grand Canyon, Arizona
The Grand Canyon swells with visitors in the summer months, but you don't have to venture very far to leave the maddening crowds behind. Park rangers say an average visit to the South Rim lasts about 15 minutes, and most people never leave the rim. We think the park is best explored on foot or by pack animal. Even if you only have a few hours, take one of the well-marked trails from the South Rim to see this geological phenomenon up close.