Grand Canyon National Park: Arizona
It's a destination that should be on everyone's bucket list, and the sheer expanse of the Grand Canyon (1,218,375 acres!) is enough to wow parents and kids alike. The South Rim is the park's most accessible area and is open year-round. Embark upon a half-day smooth-water raft trip, climb the stone Watchtower for a 100-mile view, or partake in a Grand Canyon Field Institute Learning Adventure to expand your knowledge of the area's geology, history, archaeology, and more.
Source: Flickr user Grand Canyon NPS