Northern Line: Camden Town - Kennington (via Bank)

Apparently there were plans in the late 1980s to run this part of the Northern Line, together with the High Barnet branch, as a completely separate Underground service. Maps were even produced for London Transport perusal, with the "new" line coloured a disgusting bile green.

Expediency probably overruled such a plan ever becoming reality, but there's something to be said for avoiding all the congestion created by having one line with so many branches and intersections. The Bank branch takes longer to get to Kennington than the Charing Cross branch, though it's not clear on the Underground map. Things appear to get off to a good start with trains bypassing Mornington Crescent and heading straight for...

Euston. It's then less than a minute to get to King's Cross St Pancras.

That's less than one minute to get to the King's Cross St Pancras Underground platforms. Not the station ticket hall. Nor the two titular mainline stations. Embroiled in seemingly never-ending renovation, to get from St Pancras Underground station to St Pancras mainline station you currently have to walk ages to get into the open air, whereupon you find yourself next to King's Cross mainline station, meaning you then have to walk ages to get to St Pancras and so on. This visitor-unfriendly arrangement is, however, going to be at least partly curtailed in November this year when the pompous sounding St Pancras International opens for business.

Anyhow, what you can see of the Underground station looks very nice indeed, as you'd expect for a completely redone interchange. It's topped in terms of excellence, though, by Angel.

It's undoubtedly one of my favourite stations to date, chiefly by virtue of being so cool. The air conditioning is incredible. On the (as usual) boiling hot day I was travelling this stretch of the Northern line, I was more than happy to loiter a few minutes on Angel's platforms. Or rather, The Angel. It's never been called this officially, but colloquially the extra article has been around for decades, cemented in the popular consciousness by that edition of Forty Minutes from the late 80s, The Heart Of The Angel.

Back then the station, built in 1901, was one of the worst in the land: grotty, falling apart and plagued by lifts that never worked and a rather blinkered, flippant staff (at least, this was how they were depicted on camera). Shortly afterwards, however, it was shut, completely rebuilt and now represents surely one of the best stations on the network: clean, fresh and with the longest escalators in Western Europe.

Old Street, also built in 1901, is a complete contrast: it lives under a roundabout, with no buildings on surface level at all.

There's another abandoned station just before Old Street: City Road, closed in 1922 and all building work, including the platforms, subsequently removed.

Bits of Moorgate date back to 1865, but the whole place was done over in the 1960s to better incorporate that other bit of the Northern Line which doesn't exist anymore, but at the same time does: the bit from Moorgate to Finsbury Park. Now run by First Capital Connect, I don't know why this line isn't more used or better promoted. Maybe the answer's in the question: namely, it's run by First Capital Connect. There are about seven different entrances to Moorgate from the street. This isn't strictly one of them, but it's the nicest.

Bank station, or The Bank as train drivers stubbornly call it, is lacking a proper surface entrance like Old Street. But then it is right next to the Bank of England and Royal Exchange buildings. And it's part of that sprawling, complicated jumble of tunnels that joins it and Monument station into one uber-interchange the length of an entire street. And one of the exits is *inside* the Bank of England itself. To be honest, it's quicker to walk from one to the other above ground.

London Bridge is a bad interchange if you're trying to hop from the Northern to the Jubilee Line. There's no hopping involved, more like a long schlepp. Albeit in part along one of those magical moving walkways. The Jubilee platforms are way nicer than the stuffy, skanky Northern ones, but then since they were only built a decade or so ago that's no surprise. London Bridge itself is the oldest station in the city, dating back to 1838. It's got a really imperial entrance.

Borough, on the other hand, has a tiny front door and no escalators.

Apparently things used to be far worse, with - until recently - precious little having been done by way of renovation since 1890. It looks great outside, though, with that concrete roundel on the roof.

And so to Elephant & Castle, a right roustabout of a station with, if you choose to leave by one of the two entrances, no particularly striking buildingwork at all. Typically, this was the one I went for. The other entrance is your familiar Leslie Green-styled affair, of the kind I've already encountered at Kentish Town and Mornington Crescent. No photos of that, I'm afraid. Just this glum atrium.

The end was in sight. Here's Kennington again, this time with that classic dome in shot.

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.

Northern Line: High Barnet - Camden Town

It was unseasonably hot when I tackled the other, nicer, longer "side" of what were once somewhat mystically called the Northern Heights. It was also very quiet all the way down the line. The latter helped offset the former, as well as helping to render the net-curtained realms of Finchley, Mrs Thatcher's old stamping ground, unashamedly appealing.

High Barnet, the terminus, sets the tone for the whole of the branch: unassuming, leafy, serene.

10 miles from Charing Cross and teetering on the edge of Hertfordshire, the building dates back to 1872 when it was the last stop on a line that ran from Finsbury Park to Edgware via Highgate. You're in no doubt you've come to the end of the line.

The otherwise simple business of leaving the station to head south is defiantly confusing. While I was there, three trains sat for ages at different platforms with their doors open. Fortunately I gambled correctly and selected the one that left first. Others did not. I suspect all termini tend to operate in a similar fashion.

The line sweeps down the valley of the Dollis Brook with pretty spectacular views across the surrounding countryside. Totteridge & Whetstone station looks and feels like a village corner shop.

Woodside Park is even more pastoral, with trees, flowerbeds and greenery lining both platforms, and a large piece of ground outside once used for storing coal.

Like its predecessors it was established in 1872, deep in rural Middlesex, and has its entrance at the end of a deafeningly quiet cul-de-sac. Walking into West Finchley, meanwhile, is like entering a scout hut or oversized garden shed.

Apparently it's one of the least used stations on the whole line. Built in 1933, it's still got ancient signage a-plenty.

Finchley Central is a much grander affair, and even older, dating back to 1867.

There's another entrance behind this one, up above the other side of the tracks, which, amusingly - or frustratingly depending on your circumstances - seems to require you to cross back over the lines and go through the ticket barriers (from the wrong side) to get to any ticket machines.

The whole station also resembles the deck of a ship, with a walkway running from one side to the other and the platforms below. Of course, there's another opportunity for erroneous carriage chicanery at Finchley Central, thanks to the short stub of a line which shoots off westwards towards...

Mill Hill East. And no further.

Services to and from this lonely outpost have been scaled back severely in the last year or so, meaning it's now impossible to travel from Mill Hill East direct to central London except in peak hours on weekdays. The rest of the time you have to change at Finchley Central.

When it was opened in 1867 it was part of the same line that went from Finsbury Park to Edgware, linking the two northern branches of the, er, Northern Line together into one. Tracks began to be laid to allow for electric Underground trains to run a similar service...only for World War Two to intervene. Work never progressed beyond Mill Hill East - hence the present lowly circumstances. A driver now has to go back and forth between Mill Hill East and Finchley Central hour after thankless hour.

Still, it's a spectacular journey, almost entirely above roof level, with epic views in all directions.

Back to Finchley Central, it was on down the line to East Finchley: an absolutely fantastic building, rebuilt after the 1867 original was demolished when the line was converted from steam to London Underground trains.

The present station was conceived by Charles Holden - perhaps the Underground's greatest ever designer, responsible for the dozens of iconic Art Deco stations that dot north and west London, plus Bristol Central library and the soaring, sensational Senate House in Bloomsbury.

On top of the station is a superb 10-foot tall statue by Eric Aumonier of a kneeling archer, shown as if having just released an arrow along the line towards central London. It seems totally out-of-place, and is probably ignored by 99% of passers-by. Seeing it for the first time, though, was a revelation.

I took these two photos last year, on a wet day in early July (I know: rain, in London; it can happen). It was the same day I went to Highgate:

This marks the point where the line disappears underground for the first time since High Barnet. It's another of Holden's stations, but only half-finished because the money ran out (it was originally intended to be a junction between the main line and yet another branch running off to Alexander Palace via Muswell Hill). It sits on the side of a hill with a 'low' entrance at the end of a tranquil cul-de-sac and a 'high' one up on the main road. To get from one to the other involves a ludicrously giant escalator ride.

From art to artlessness: Archway was my first disappointment of the day.

In contrast to just about everything on the line up till now, it's a dirty, ugly building hailing from 1907 which, despite benefiting from some Charles Holden tinkering in the 30s, now squats beneath a giant tower block by a menacingly busy road filled with poky shops.

Tufnell Park, another 1907 vintage, at least has a bit of Edwardian flare still intact.

While Kentish Town, its exterior soldiering on since 1868, has much more swagger and grandeur:

South Kentish Town was built in 1907, was shut down during a strike at a nearby power station in 1924, and for some reason never opened again. Apparently it was never really used in the first place. John Betjeman later wrote a short story called, appropriately, South Kentish Town, about a passenger who became trapped in the disused sation when a train stopped there by mistake.

And so to Camden Town, the point where both Northern Line branches collide, and the end of this - largely - tranquil excursion. The lift still wasn't working.

Northern Line: Edgware - Camden Town

Since this was the nearest branch to where I live, it seemed the obvious place to start. Indeed, Hendon Central station is 60 seconds from my flat, albeit round a couple of corners and behind some conveniently sound-absorbing buildings.

My feelings towards the Northern Line change daily, chiefly depending on whether it's a) running on time b) running enough trains to meet demand or c) running at all. The carriages were built in 1996, but somehow look and feel much older. Maybe it's a side-product of over-familiarity, but the seats on, say, Piccadilly Line trains seem much more comfortable and the carriages on the Jubilee Line far more spruce and slick, even though the former hail from 1973 and the latter from, again, 1996.

One thing is certainly true: the Northern Line is the hottest and dirtiest line of them all. Riding its trains last summer was an abominably sweltering experience. Even in the middle of winter, its carriages and all of its below ground stations are like saunas.

I made this journey on Good Friday, something that bore no relation to anything except for what I found outside Edgware station:

Nobody was paying it any attention. The station itself, built in 1924, is your textbook terminus, right down to the circular service road that allows buses and cars to set down and pick up en route elsewhere.

The building is unchanged since construction; everything else around it is not, having originally been plain open fields and countryside.

Now there are shopping centres and busy roads and housing developments and, well, a hell of a lot of people just standing about. The building seemed lost, overlooked, unnoticed. Everyone took it for granted, but nobody seemed happy to use it. I liked the old fashioned swing doors at the entrance, which reminded me of the ones outside my secondary school assembly hall.

I walked down the A5 to Burnt Oak, originally called Burnt Oak (Watling) after the old name for the A5: Watling Street. There is no oak, and nothing is burnt.

Like Edgware, it was opened in 1924, designed by the same person (Stanley Heaps) and has the same antique swing doors. It also has this fantastic construction on a wall outside, announcing the station's presence to the entire neighbourhood:

Colindale station, by contrast, is a dump:

The original building, once more hailing from 1924 and the handiwork of Heaps, was destroyed by bombing in the Second World War. Nobody bothered to replace it properly, and to this day the station remains a grim entrance in a grim row of shops.

Still, if you take the train south from Colindale and look to the left side of the track, a familiar object awaits you, lurking on one edge of the Metropolitan Police training centre:

I took this photo of the next station on the line, Hendon Central, on the day in early February when London was hit by a blizzard of snow:

The building is being refurbished at the moment and is about to gain - gasp! - a lift, thereby making it the only station on the Edgware branch of the Northern Line with full wheelchair access. Two flower sellers work in the atrium. It's a fine building, and is another Stanley Heaps creation, dating from 1923 - as is Brent Cross:

It's only been called Brent Cross since 1976, gaining its second word when the eponymous shopping centre opened nearby. I say nearby, but it's actually ridiculously difficult to reach on foot, and despite being less than a mile away as the crow flies, you need to get a bus if you want to reach the shops with your sanity intact.

The station also has a really subtle side entrance that you get to via an unassuming pathway in a completely ordinary suburban street:

Golders Green station, however, is as assuming as they come: a huge building in the middle of the town doubling as a bus interchange.

Opened in 1907, it was for a while the end of the Charing Cross, Euston and Hampstead Railway, and is still the main depot for the whole of the Northern Line. Semaphore signalling apparently continued at the station until 1950. Just outside is a seminal venue, sadly no longer in use: the Golders Green Hippodrome, former home of the BBC Concert Orchestra:

I came here in December 1994 to attend a "secret" gig by, of all people, The Beautiful South. I won tickets in a Radio 1 competition.

Travelling south from Golders Green the Northern Line disappears completely underground for the first time since Edgware (apart from a short tunnel north of Colindale).

A minute or so into the journey you pass the half-built remains of the proposed North End or Bull And Bush station, which would have enabled passengers direct access onto Hampstead Heath, as opposed to now where you have to get off at Hampstead and walk miles.

Not that it's easy to get off at Hampstead, or indeed get out of the station. It's a hopelessly poky, shambolic construction squeezed onto a busy road junction. The fact it's currently being completely rebuilt doesn't help, or make for a good photo:

Hampstead does, however, boast the longest lift shaft of any London Underground station, and hence wins a mention in the Guinness Book of Records for being the deepest station in the world (192 feet below the ground).

This project being merely a snapshot of the Underground, I have to take stations as I find them. Even if there's almost nothing to find:

More refurbishment at Belsize Park. Like Hampstead it was opened in 1907, was designed by Leslie Green, and sits on the same road as that and its two subsequent stations - a road I chose to walk down rather than continually hop on and off trains deep below the ground. About ten minutes later I was at Chalk Farm:

Thankfully this wasn't under wraps, and the wonderful old-fashioned font and architecture was open to the sunshine.

Ten minutes further down the road was Camden Town, the end of my journey, and approximately 35 million people:

There was a right roustabout going on outside this station, which is probably par for the course on a de facto weekend. Still, this was a close as I could get by way of a decent photograph. The station itself, like Chalk Farm, dates from 1907 and is once more the handiwork of Leslie Green. Like Belsize Park, it has an air-raid shelter underneath its platforms.

Inevitably, inside the building it was chaos, with an escalator broken, the Charing Cross branch closed, people shouting, lost tourists and the rising temperature making for a far from amiable embarkation.

Time to head home.