San Francisco International Airport (IATA: SFO, ICAO: KSFO, FAA LID: SFO) is 13 miles (21 km) south of downtown San Francisco, California, near Millbrae and San Bruno in unincorporated San Mateo County. It has flights to points throughout North America and is a major gateway to Europe and Asia.
SFO is the largest airport in the Bay Area and the second busiest in California, after Los Angeles International Airport. In 2013 it was the seventh busiest in the United States and the twenty-second busiest airport in the world by passenger count. It is the fifth largest hub for United Airlines and functions as United's primary transpacific gateway. It also serves as Virgin America's principal base of operations. It is the sole maintenance hub of United Airlines, and houses the Louis A. Turpen Aviation Museum.