Aerial view (through control tower windows) showing expanse of airport land with airliners at London Heathrow. A panoramic view of the airfield and parked and taxiing airliners. Consisting of five terminals on a site that covers 12.14 square kilometres (4.69 sq mi). London Heathrow is a major international airport, the busiest airport in the United Kingdom and the busiest airport in Europe by passenger traffic. It is also the third busiest airport in the world by total passenger traffic, handling more international passengers than any other airport around the globe.