BWI stands for Baltimore/Washington International Thurgood Marshall Airport. It is an international airport located in Anne Arundel County, Maryland, 9 miles south of downtown Baltimore and 30 miles northeast of Washington, D.C. . BWI is one of three major airports that serves the Washington–Baltimore metropolitan area, along with Dulles International Airport (IAD) and Ronald Reagan Washington National Airport (DCA) . It is the busiest airport in the Baltimore-Washington metropolitan area and the 22nd-busiest airport in the United States as of 2021. BWI has more than 700 daily domestic and international flights serving more than 75 cities nonstop.