Watford Junction (WFJ) to Harlesden (HDN) train with London Overground

London Overground is a train company based in the United Kingdom. It operates a network of suburban rail services in and around Greater London. The services run from early morning until late at night, with some lines running 24 hours a day. The trains come in a variety of types, including the Class 378 Capitalstar, Class 172 Turbostar, Class 315, Class 317, Class 508 and Class 700 Desiro City. London Overground offers a range of ticket types, including single, return, off-peak and super off-peak tickets. Onboard facilities include air-conditioning, Wi-Fi, power sockets and CCTV. The most popular routes for London Overground are from Euston to Watford Junction, from Liverpool Street to Enfield Town, and from Clapham Junction to Stratford.

The London Underground, affectionately known as \the Tube,\" is the world's oldest underground railway system, opening in 1863. It's a rapid transit system serving Greater London and parts of the adjacent home counties, with 11 lines and 272 stations across 402 km of track. The network is divided into nine zones, with fares varying by distance, time of day, and payment method, with Oyster cards or contactless payments being the cheapest.The London Underground utilizes two main types of trains: \"Tube trains\" for deep, narrow tunnels and \"Sub-surface trains\" for wider, shallower tunnels. While initially steam-powered, all passenger trains have been electric multiple units since the early 1900s. The Victoria Line was the first automatic passenger railway in the world, and other lines now also use Automatic Train Operation (ATO)."