The worlds oldest underground public transport system and some days it feels just like that. Delays and strikes aside the Tube is usually the fastest way to get around. Oyster cards and tickets are available for one trip, return, one day, three day, weekly, monthly and year long travel cards. Prices correspond to the number of zones you want to travel in and are far cheaper with the Oyster option. Oyster cards can be used on both public buses and the tube. There are visitor cards available if you are in town for a limited time. Cards can be topped up in the machines or at the tellers. You must touch in and out on the tube.