London Underground Buses, Tramlink, London Overground, London River Services and Docklands Light Railway. Crossrail, due to open in 2019, is to be identified with a roundel. The 100th anniversary of the roundel was celebrated in 2008 by TfL commissioning 100 artists to produce works that celebrate the design. Seventy of the 270 London Underground stations use buildings that are on the Statutory List of Buildings of Special Architectural or Historic Interest, and five have entrances in listed buildings. The Metropolitan Railway's original seven stations were inspired by Italianate designs, with the platforms lit by daylight from above and by gas lights in
London Underground bring the total of step-free stations to over 100. In mid-2012 London Underground, in partnership with Virgin Media, tried out Wi-Fi hot spots in many stations, but not in the tunnels, that allowed passengers free internet access. The free trial proved successful and was extended to the end of 2012 whereupon it switched to a service freely available to subscribers to Virgin Media and others, or as a paid-for service. It is not currently possible to use mobile phones underground using native 2G, 3G or 4G networks, and a project to extend coverage before the 2012 Olympics was abandoned because