Atlanta is the capital and most populous city of the U.S. state of Georgia. It is the county seat of Fulton County and extends into neighboring DeKalb County. With a population of 498,715 at the 2020 census and an estimated 529,110 in 2025, Atlanta is the eighth-most populous city in the Southeast and the 36th-most populous city in the United States. Atlanta is classified as a Beta+ global city. The Atlanta metropolitan area has an estimated population of over 6.4 million and is the sixth-largest metropolitan area in the United States. Situated among the foothills of the Appalachian Mountains at an elevation of just over 1,000 feet (300 m) above sea level, Atlanta features a unique topography that includes rolling hills, lush greenery, and the densest urban tree coverage of any major city in the United States.