Fare zone 1 is the central zone of Transport for London's zonal fare system used by the London Underground, London Overground, Docklands Light Railway and National Rail. For most tickets, travel through Zone 1 is more expensive than journeys of similar length not crossing this zone. The zone contains all the central London districts, most of the major tourist attractions, the major rail terminals, the City of London, and the West End. It is about from west to east and from north to south, approximately 45 km².