San Francisco International Airport is a universal air airport 13 miles south of downtown San Francisco, California, close Millbrae and San Bruno in unincorporated San Mateo County. It has flights to focuses all through North America and is a noteworthy portal to Europe and Asia. San Francisco International airport is the biggest airport in the San Francisco Bay Area and the second busiest in California, after Los Angeles International Airport. In 2013 it was the seventh most crowded airport in the United States and the twenty-first most crowded on the planet by traveler count. It is the fifth biggest center point for United Airlines and operate as United's essential transpacific portal.