How many zones is the London underground network divided into?

W: Underground tickets are available at all underground stations. Ticket prices for the underground vary according to the distance you travel. The network is divided into five zones, a central zone and four outer zones. Generally, your fare will increase, the more zones you travel through. You must buy your ticket before you start your journey, from a ticket office or machine. Keep your ticket for inspection and collection at your destination.
     The easiest and most economical way to travel around London is with a travel card. This gives you the freedom of London’s trains, tubes and buses in whichever zones you choose. It’s perfect for the visitor because one ticket combines travel on the trains of Network Southeast with the underground, Dockland Light railway and most London buses. It’s more convenient than buying separate tickets for each journey. Travel cards are available from any train or tube station.
     A one-day travel card is ideal for a day’s shopping, sightseeing, and all tourist trips in London. You can travel anywhere you like within the vast 650 square mile travel card area. No need to keep queuing for tickets or carry a pocketful of change for ticket machines, just use whatever form of transport that suits you best for any combination of trips. One-day travel cards can be bought from staffed train or tube stations after 9:30 a.m. on weekdays and any time at weekends.
    Travel card season tickets include 7-day, monthly and annual tickets. This is the modem, convenient and flexible ticket for your daily journey to work. For travel card season tickets, please bring a passport size photograph with you. Smoking is not allowed anywhere on the underground. Smoking is permitted, however, at the back of the upper deck of buses.