<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Northern line is a London Underground line that runs essentially from south - west to north London, with two branches through central London and three in the north . Its southern section runs from Morden in the borough of Merton to Kennington in Southwark, where it then divides into two central branches, one via Charing Cross in the West End and the other via Bank in the City . The central branches re-join at Camden Town, where the line again divides into two branches, one to High Barnet and the other to Edgware in the borough of Barnet . On the High Barnet branch there is a short single - track branch to Mill Hill East only . </P> <P> For most of its length it is a deep - level tube line . The portion between Stockwell and Borough opened in 1890 and is the oldest section of deep - level tube line on the Underground network . There were about 252 million passenger journeys recorded in 2011 / 12 on the Northern line, making it the second - busiest on the Underground . (It was the busiest from 2003 to 2010 .) It is unique in having two different routes through central London . Despite its name, it does not serve the northern-most stations on the network, though it does serve the southern-most station, Morden, as well as 16 of the system's 29 stations south of the River Thames . There are 50 stations in total on the line, of which 36 have platforms below ground . </P>

Where does the northern line start and end
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