Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers 42,169 square miles (109,220 km2), making it the 36th-largest by total land area. The Appalachian Mountains dominate the eastern part of the state, and the Mississippi River forms the state's western border. The Great Smoky Mountains National Park, the nation's most visited national park, is headquartered in the eastern part of the state, and a section of the Appalachian Trail roughly follows the Tennessee-North Carolina border. Other major tourist attractions include Elvis Presley's Graceland in Memphis and the Tennessee Aquarium in Chattanooga.