Northern Line: Camden Town - Kennington (via Charing Cross)

After coming together in rather disjointed union at Camden Town, almost immediately the Northern Line splits again, one route heading south through the West End, the other heading south via the City. The former, seemingly forever referred to as the Charing Cross Branch, appears to get you south of the river faster than the other one, but as with anything to do with the Northern Line, appearances have nothing to do with reality. The City branch, for instance, gets you to Euston quicker than the Charing Cross branch, thanks to the latter making its first stop at...

Opened in 1907, it's always been one of the lesser-used Underground stations, so much so that when it closed for six years in the 1990s nobody really noticed. Fittingly its re-opening was attended by the surviving practioners of the eponymous I'm Sorry I Haven't A Clue game. There's a plaque to Willie Rushton somewhere or other. I've never seen anyone get off at Mornington Crescent. Fact.

After Euston, gateway to the north...

...with its ludicrously overheated Underground tunnels and statue of the London-Birmingham Railway founder Robert Stephenson, it's but a particularly aeronautical stone's throw to...

Warren Street. Many's the time I've got off a train early or walked on to Euston rather than plunge into the humid depths of this dank, dark station. Its platforms are badly-lit and like an oven, even in winter. It's another 1907 vintage, ditto Goodge Street:

As is suggested by the fact it looks like it's squatting in an otherwise unexceptional block of flats, the station has no room for escalators, only four worryingly tatty lifts. It's another station that has a World War 2 deep-level air-raid shelter underneath it - the one, in fact, from which Eisenhower broadcast the announcement of the invasion of France on 6th June 1944.

To be honest, if you're travelling along any part of this branch of the Northern Line, it's quicker to walk. From Warren Street to Embankment you get stations every five-10 minutes on foot. Tottenham Court Road is even less of a stone's throw from Goodge Street.

Another manky station, befitting the clatter and grime that gets whipped up on Oxford Street, I don't think I've ever used this station and not felt myself physically getting dirtier and sweatier the further down I go. The infrastructure dates back to 1900. The smells do too. Perhaps if the long-mooted Crossrail service ever gets built, the whole station will get totally rebuilt.

Leicester Square is far better, though I'm probably speaking more out of familiarity with the station I used for a year or so to get to work.

Leslie Green was the architect of the original 1906 building; Charles Holden gave it a spring clean. There used to be a busker in this station who played the harp. The story of Charing Cross is a melee of name-changes, station-mergers and pretend-connections. The present day station is actually two combined: Trafalgar Square, originally on the Bakerloo Line, and Charing Cross, solely on the Northern Line. There was soon another station to the north, Charing Cross (Strand), which quickly lost its first two names, and Charing Cross (Embankment), which lost its last name. Then when the Jubilee Line was extended through to the area in the 1970s, everything was rolled up into one. Except Embankment, as it was now called, which still exists - less than 60 seconds walking distance from its parent, ten times as far if you use the Underground, and quicker to reach than the end of this paragraph. Under the river it's Waterloo... ...and then on to Kennington: Newly refurbished, it still bears traces of its construction in 1890 as part of London's first deep-level line, the City & South London Railway. It's also a pleasantly leafy and lazy rendezvous where the Northern Line becomes one again.