Central line (London Underground) Central line (London Underground) The Central line is a London Underground line that runs through central London, from , Essex, in the north-east to and in the west. Coloured red on the Tube map, the line serves 49 stations over , which makes it the longest Tube line. It is also one of only two lines on the Underground network to cross the Greater London boundary, the other being the Metropolitan line. One of London's deep-level railways, Central line trains are smaller than those on British main lines. The line was opened as the Central London Railway in 1900, crossing
Urban rail in the United Kingdom and Western England. Stations within London are served by two or four trains per hour. The London Overground (often shortened to "Overground") is operated by Arriva Rail London under a concession let by Transport for London, which owns the London Underground. The Overground includes the Watford Local, North & West London, East London & South and the Gospel Oak to Barking lines. It is the only National Rail service shown on the London Underground map. All stations are served at least every 20 minutes, with stations between and on the East London Line having 16 trains per hour in each