The fast-growing city of Atlanta is a transportation hub for the U.S. and the world. The official population is about 420,000, but the metro area has grown to about 4.1 million. Atlanta is also known as a banking center and is home to the world headquarters of 13 Fortune 500 companies. The ever-changing downtown skyline includes skyscrapers constructed in the Midtown, Buckhead, and outer perimeter business districts around I-285.