The DC Airport is served by two airports: Dulles International Airport (IAD) and Ronald Reagan Washington National Airport (DCA). Dulles International Airport is located in Loudoun County, Virginia, and is the largest airport in the Washington metropolitan area. It is named after John Foster Dulles, the 52nd Secretary of State. The airport code for Dulles is IAD, which stands for International Airport Dulles. Ronald Reagan Washington National Airport is located in Arlington County, Virginia, and is the closest airport to downtown Washington, D.C. It is named after the 40th President of the United States, Ronald Reagan. The airport code for Reagan is DCA, which stands for District of Columbia Airport.