Wimbledon, London Spencers attempted to get parliamentary permission to enclose the common as a new park with a house and gardens and to sell part for building. Following an enquiry, permission was refused and a board of conservators was established in 1871 to take ownership of the common and preserve it in its natural condition. Transport links improved further with railway lines to Croydon (Wimbledon and Croydon Railway, opened in 1855) and Tooting (Tooting, Merton and Wimbledon Railway, opened in 1868). The District Railway (now the London Underground District line) extended its service over new tracks from Putney in 1889. In the
London Underground persist to this day. "" has a single-player level named "Mind The Gap" where most of the level takes place between the dockyards and Westminster while the player and a team of SAS attempt to take down terrorists attempting to escape using the London Underground via a hijacked train. The game also features the multiplayer map "Underground", in which players are combating in a fictitious Underground station. The London Underground map serves as a playing field for the conceptual game of Mornington Crescent (which is named after a station on the Northern line) and the board game "The London Game".