Vast, magnificent and inarguably beautiful, the Grand Canyon is easily Arizona’s most distinguishable landmark – and a natural wonder that you simply have to see to believe. Stretching 277 miles from end to end, steep, rocky walls descend more than a mile to the canyon’s floor, where the wild Colorado River traces a swift course southwest. Grand Canyon National Park is home to much of the immense Grand Canyon, with its layered bands of red rock revealing millions of years of geological history. The park’s central feature is the Grand Canyon, a gorge of the Colorado River, which is one of the Seven Natural Wonders of the World. Nearly six million people visit the National Park every year. This makes Grand Canyon National Park the second most visited park in the U.S. after the Great Smoky Mountains national park. Aside from casual sightseeing from the South Rim above sea level, skydiving, rafting, hiking, running, and helicopter tours are popular. Tourists wishing for a more vertical perspective can go skydiving, board helicopters and small airplanes in Boulder, Las Vegas, Phoenix and Grand Canyon National Park Airport (seven miles from the South Rim) for canyon flyovers.