Heathrow Airport, called London Airport until 1966 and now known as London Heathrow, is the main international airport serving London, England. It is the largest of the six international airports in the London airport system. The airport is owned and operated by Heathrow Airport Holdings. In 2021, it was the seventh-busiest airport in the world by international passenger traffic and eighth-busiest in Europe by total passenger traffic. Heathrow was founded as a small airfield in 1929 but was developed into a much larger airport after World War II. It lies 14 miles west of Central London on a site that covers 12.27 square kilometres. It was gradually expanded over seventy-five years and now has two parallel east-west runways, four operational passenger terminals and one cargo terminal. The airport is the primary hub for British Airways and Virgin Atlantic.