Grand Canyon National Park is a national park of the United States located in northwestern Arizona, the 15th site to have been named as a national park. The park's central feature is the Grand Canyon, a gorge of the Colorado River, which is often considered one of the Wonders of the World. The park, which covers 1,217,262 acres of unincorporated area in Coconino and Mohave counties, received more than 4.7 million recreational visitors in 2023. The Grand Canyon was designated a World Heritage Site by UNESCO in 1979. The park celebrated its 100th anniversary on February 26, 2019.