Atlanta (at-LAN-tə) is the capital and most populous city in the U.S. state of Georgia. It is the seat of Fulton County, and a portion of the city extends into neighboring DeKalb County. With a population of 510,823 living within the city limits, Atlanta is the eighth most populous city in the Southeast and 37th most populous city in the United States according to the 2020 U.S. census. It is the principal city of the much larger Atlanta metropolitan area, the core of which includes Cobb, Clayton and Gwinnett counties, in addition to Fulton and DeKalb. Metro Atlanta is home to more than 6.3 million people (2023 estimate), making it the sixth-largest U.S. metropolitan area. Situated among the foothills of the Appalachian Mountains at an elevation of just over 1,000 feet (300 m) above sea level, Atlanta features unique topography that includes rolling hills, lush greenery, and the densest urban tree coverage of any major city in the United States.