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, the more zones you travel through, the higher your fare will be. You must buy your ticket before you start your journey, from a ticket office or machine. Kecp your ticket for inspection and collection at your destination. The easiest and most economical way to trayel 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 visitors because one ticket combines travel on the trains of Network Southeast with the underground, Dockland Light railway and most of London buses. It's more convenient than buying separate tickets for cach journey. Travel cards are available from any train or tube station. Travel card season tickets include seven-day, monthly and annual tickets. This is the modern, convenient and flexible ticket for your journey. For travel card season tickets, please bring a passport-size photograph with you.