Huntsville International Airport (HUN) is the tenth busiest airport in the United States, serving over 7.5 million passengers annually. The airport has three runways and is located in Huntsville, Alabama, about halfway between Montgomery and Birmingham. The airport was opened in 1950 and underwent a $500 million renovation in 2011. The renovation added a new concourse, a new terminal building with airside facilities, a new parking garage, and new public transportation links to the city. The airport also added a new international arrivals area, which includes customs and immigration facilities.