Ans. You can travel through red buses, black cabs, London Tube or through subway tunnel. Oyster is a plastic smartcard which can hold pay as you go credit, Travelcards and Bus & Tram Passes. You can use an Oyster card to travel on bus, Tube, tram, DLR, London Overground, TfL Rail, Emirates Air Line, River Bus services and most National Rail services in London.