The Metropolitan line is a London Underground line that runs from Aldgate, in the City of London, to Amersham and Chesham in Buckinghamshire, with branches to Watford in Hertfordshire, and Uxbridge in the London Borough of Hillingdon. Coloured magenta (Pantone 235) on the tube map, the line is 41.4 miles (66.7 km) in length and serves 34 stations. The section between Aldgate and Baker Street is shared with the Circle and Hammersmith & City lines; that between Rayners Lane and Uxbridge with the Piccadilly line; and that between Harrow-on-the-Hill and Amersham with Chiltern Railways. Just under 67 million passenger journeys were made on the line in 2011/12. The line is one of only two London Underground lines to cross the Greater London boundary, the other being the Central line.