Consider buying an Oyster card when you arrive in London, a swipe card that can be topped up with money and used on any London public transport. Cards can be purchased at the train station or counters inside the arrivals hall. From Heathrow, take the Piccadilly Line directly to Piccadilly Circus, Leicester Square or Covent Garden. From Gatwick, the quickest way is via the Gatwick Express that costs S$ 35 (≈£20) or opt for the cheaper Thameslink train. The Stansted Express operates from Stansted to London Liverpool Street and costs S$ 30 (≈£17).