High Quality Content by WIKIPEDIA articles! The Bakerloo line is a line of the London Underground, coloured brown on the Tube map. It runs partly on the surface and partly at deep level, from Elephant and Castle in the south-east to Harrow Wealdstone in the north-west of London. The line serves 25 stations, of which 15 are underground. Its name comes from the fact that its route serves Baker Street and Waterloo.