The document lists the top ten busiest airports in the world based on total passenger traffic, with Hartsfield-Jackson Atlanta International Airport having the most passengers annually since 2000. London has the busiest city airspace with two of its airports, London Heathrow and London Gatwick, regularly in the top ten. The top three airports are Hartsfield-Jackson Atlanta International, O'Hare International in Chicago, and London Heathrow.