The London Underground began life in 1863 as the Metropolitan Railway, ferrying passengers from the great railway terminals of Euston, King's Cross and Paddington to the City of London.
Back then, you'd buy a paper ticket before boarding one of the steam-powered, gas-lit, wooden trains. Today, you can still buy paper tickets - but there are cheaper, quicker and more convenient ways to pay for your journey.
First came Oyster, the contactless smart card. In 2014 came contactless bank cards and mobile NFC. And who knows what the future will bring?
Watch our animation, which traces the history of ticketing on the world's oldest underground railway.