Tags: Railway Line.
The Northern line is a London Underground line coloured black on the Tube map.For most of its length it is a deep-level tube line. There were about 252310000 passenger journeys in 2011/12 on the Northern line making it the second busiest line on the Underground. (It was the busiest from 2003 to 2010.) It is unique in having two different routes through central London – the Charing Cross branch serving the central part of zone 1 and the Bank branch serving the eastern part of that zone.
