Miami-Dae County (often referred to as simply Miami or Dade) is a county located in the southeastern part of the state of Florida. The United States Census Bureau estimates that the county population was 2,402,208 in 2006, making it the most populous county in Florida and the eighth-most populous county in the United States. It is also Florida's 2nd largest county in terms of land area, with 1,946 square miles. The county's population makes up approximately half of the South Florida metropolitan area population and holds most of the principal cities of South Florida, making it the most important of the three counties that make up the area. The county seat is the city of Miami.