The Hammersmith & City line of the London Underground runs between Hammersmith and Barking. Coloured salmon pink on the tube map, it serves 29 stations in . It runs below ground in the central section between Paddington and Bow Road; between Farringdon and Aldgate East it skirts the City of London, the capital's financial heart. The tunnels are just below the surface and are a similar size to those on British main lines. Most of the track and all stations are shared with the District, Circle or Metropolitan lines, the other parts of London Underground's sub-surface railway, and over 114 million passenger journeys are made each year on this line and the Circle line. Of the 29 stations served, 10 are below ground.