| Existing comment:
The United States' 15th oldest national park is Grand Canyon National Park. Named a UNESCO World Heritage Site in 1979, the park is located in Arizona. The park's central feature is the Grand Canyon, a gorge of the Colorado River, which is often considered one of the Seven Natural Wonders of the World. The park covers 1,217,262 acres (1,902 sq mi; 4,926 km2) of unincorporated area in Coconino and Mohave counties. |