Heathrow - The UK's biggest airport is located at Heathrow, contributing to over £5 billion to our economy each year. It could almost be a self-contained city with its population of 60,000 workers. What is now today a massive architectural and engineering feat started life as a small grass airfield, originally used for flying tests. In 1944 it was taken over by the Air Ministry to be transformed into a transport base for the Royal Air Force during the war but before it was completed the war ended and Heathrow's massive commercial potential, being so close to the capital, was its starting point to developing into the major international airport we know today. Heathrow airport is just 15 miles west of central London and there are great transport links with the city. All terminals can be easily reached from the M25 and M4 motorways and there are both short stay and long stay parking options. The London Underground has two stations from which all four terminals can be accessed on the Piccadilly line and the Heathrow Express operates non stop and direct from Paddington station to the airport. Close to Heathrow airport visitors can find such attractions as the world famous Ascot racecourse which holds the Royal meeting every June and Europe's largest polo club, the Guards Polo Club. Family attractions include the Queen's official residence, Windsor Castle and the rides, roller coasters and shows of Legoland.