Some facts about Heathrow Airport

From the first episode of the BBC4 TV series 'The Secret Life of the Airport':

1. The original airport was built (in the late 1940s) with six runways (each about one mile in length) in a star of David form. This was because contemporary airplanes needed to take off into the wind, in order to gain lift. The two east-west runways were extended during the early 1970s, and the other runways were removed to allow for terminal expansions or turned into taxiways
2. The three original terminal buildings were built during the 1950s and 1960s at the centre of the airport, i.e. within the internal hexagon. Tunnels were built under the runways to allow access. One of the flaws in this design was lack of space to build carparks - the original architects had assumed that air travel would always be reserved for the rich, who would be driven to the terminal buildings by their chauffeurs. Terminals 4 and 5 were built later outside the original star, on the south and west of the airport respectively.