The Grand Canyon is located in northern Arizona, northwest of the city of Flagstaff. The canyon measures over 270 miles long, up to 18 miles wide and a mile deep, making it one of the biggest canyons in the world.
Grand Canyon rivals Yellowstone to be the most famous national park in the world. It is the second most visited national park in the US (after the Great Smoky Mountains), and contains 277 miles of the Colorado River together with many, branched tributary canyons; a lifetime could be spent exploring.