Central line (London Underground) that the transport benefits of a Park Royal station on the Central line are not sufficiently high to justify the costs of construction. 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,
History of the London Underground Farringdon to King's Cross in 1852 . Although the plan was supported by the City of London, the railway companies were not interested and the company struggled to proceed. In 1854 the Metropolitan Railway (also known as the Met) was granted permission to build an underground line at an estimated cost of £1 million. With the Crimean War under way, the Met found it hard to raise the capital, and construction did not start until March 1860. The railway was mostly built using the "cut-and-cover" method from Paddington to King's Cross; east of King's Cross it was built by tunnelling