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–Aylesbury line west, while the Aylesbury line continues north parallel to the underground lines. The line then joins the Metropolitan line tracks a few yards south of Harrow-on-the-Hill station and shares this track with the London Underground's fast Metropolitan line services to Amersham from Baker Street. Beyond Moor Park, the line to Watford diverges. Between Rickmansworth and Chorleywood, the M25 motorway crosses on a viaduct. After Chalfont & Latimer station, the Chesham branch diverges, and the main line continues to Amersham, the terminus for Metropolitan line trains. Beyond Amersham, the line returns to Network Rail control and runs northwest to Aylesbury, following