Saturday lunchtime at the Cat and Mutton pub in Broadway Market is dominated by the television. The set sits in the corner, above a disco table decorated, bizarrely, with a Confederate flag and a caricature of Ronald Reagan.

Last Saturday, four old men in flat caps were watching the racing, comparing notes about which horse they had backed. As the race progressed and the favourite flagged, the foursome became increasingly animated.

'Go-o-o on my son,' one of them shouted. 'Get yer whip aht.'

As an unfancied nag began to make a break from the back of the pack, one of the men, who had just taken a big swig of beer, leapt from his seat in excitement. Such excitement, in fact, that he spluttered over his ale and threw up his breakfast into his pint pot.

This is what goes on in the pub which is the model for the Queen Vic in television's EastEnders. Not much in the way of adultery, incest, murder or rape, but plenty of incident over the 1.30 at Market Rasen.

That's the thing about EastEnders: it is not the real East End of London. There are no angry dogs haunting the open spaces; none of the characters says 'innit' at the end of every sentence; there is not even a television set offering Sky live matches in the Vic. The backdrop to the shenanigans that fill our screens every Tuesday and Thursday night is fictional, too. The breeze-block and plywood set can be found to the north of London on a lot at Elstree Studios.

'It was built nine years ago as a temporary structure,' said Nick Callan, one of the programme's designers. 'As it's outdoors, open to the elements, we're constantly putting in new roofs and making running repairs.

'The market stalls have to be put away after shooting, like a real market. Mark's fruit and veg stall is stocked with real stuff every time we use it.'

Unlike Granada Television which - as part of its lucrative studio tour - allows trippers to snoop around the cobbles of Coronation Street and buy a pint at the Rovers Return, you cannot have a peek at this erzatz East End. The BBC keeps it out of bounds, lest light-fingered visitors walk off with a tasty item from Sanjay's clothing stall.

But the inspiration for every fixture, fitting and bar stool can be inspected - free. Indeed, in the new year the Borough of Hackney, as part of its City Challenge spruce-up, is to encourage visitors to see the real East End for themselves. All you have to do is take a bus along the Balls Pond Road into Dalston.

When Keith Harris, the BBC designer who later built the Eldorado set, was looking for inspiration for a fictional borough of Walford, he knew exactly where to look: his first stop was Fassett Square. In this neat rectangle of bay-fronted Victorian terraces surrounding a small communal garden, he found his Albert Square.

Indeed, he made such a good job of reproducing the place that, when you step off the number 22B bus and walk past the Queen Elizabeth pub into the square, you half-expect to see Michelle engaged in a love tryst on the garden benches, Frank chasing Ricky down the road in a fume, Aidan and Mandy patching up their squat or Arthur emerging with his adulterous thoughts from No 45.

Instead, you see a couple of small boys kicking a football against a garden wall, a man up a ladder worrying at a gutter and two cats sparring under a jacked-up car.

'They may have come here for architectural ideas,' said one resident who, unlike most of the programme's cast, was anxious to remain anonymous. 'But I don't think they come here to get inspiration for scripts. In the past eight years we've only had a death, a couple of injuries and a teenage pregnancy. But you get those once a week on the programme.'

In fact, one of the most extraordinary things that has happened in the square was five years ago when Tom Watt who, as the hopeless barman Lofty at the start of the series, fetched up in the square and started signing autographs in the little central garden. He could not do that now: the garden is locked and only residents have keys.

'We used to get quite a few tourists wandering through with their A-Zs, looking lost and asking where the Queen Vic was,' said the anonymous local, explaining the lock-out. 'But when they realised they weren't going to see Den or Angie, they moved on pretty quickly.'

This is not the part of the East End that makes it on to television documentaries. There are no crack dealers plying their trade on the corner, no cockroach-infested tower blocks on the horizon, no Arts Council-funded sculptors filling houses with concrete down the road. It is quiet, residential; if you were an estate agent you would say it was 'desirable'.

Fassett residents tend to have decidedly untelevisual matters on their minds: the state of the lime trees in their communal garden, for instance, which have just been pollarded to stop them getting completely out of hand, and the fate of the side of the square occupied by the four-storey Thirties frontage of the long-derelict German Hospital.

'For some reason the thing got listed,' said our local. 'To be honest, the best thing to do would be to take the bulldozer to it. But, of course, thanks to some local bureaucrat who reckons this monstrosity is worth keeping, we can't'

The dull, grey-brick hospital is not the only part of the square that Mr Harris did not include in his set. In a neat bit of social engineering, he played with Dalston, squeezing three or four elements of it into one self-contained filming unit.

So the railway running past the back of Fassett Square is in a cutting rather than on the viaduct that clatters across Albert Square (bearing Tube trains of which, incidentally, there is no evidence in the Borough of Hackney). And the cutting carries British Rail's North London Line which, as anyone who has tried to commute on its oft-cancelled services will appreciate, is the quietest possible railway line to live beside.

Except once a night, at about 2am, when a train louder than a Frank Butcher temper tantrum trundles past. Laden with what sounds like 85 lead-filled carriages. This train rattles teacups, window frames and rib-cages. Rumour has it that it is chocker with spent nuclear fuel, entombed in tons of protective concrete. Which explains the 'No nukes' graffiti around the square.

Without a viaduct, the square is spared one important aspect of East End, and indeed EastEnders, life: the under-the-arches garage. In the show, such a garage is the haunt of Phil and Grant, the shaven-headed brothers who in the real East End would be obergruppenfuhrers of the local branch of the British National Party.

Travel east along the railway from the square and you will soon find a viaduct, and beneath it the arches are alive with enterprise. Just under Hackney Central station, there is a good bistro called Down's: it occupies three or four arches where, since it is not open at 2am, you can dine reasonably unpolluted by noise.

For the most part, however, the arches are filled with Grant and Phil lookalikes. One or two of them must, by the law of averages, be engaged in wholly legal garage work, offering value-for-money services, though few car-owning East Enders have yet found such paragons.

I have steered clear of arch garages since dealings a couple of years ago over my MG roadster, one of a class act with metal bumpers but very few moving parts in its engine compartment. Finally, exasperated by an almost daily acquaintance with the AA, I called an under- the-arch dealer in Hackney, whose large sign said he would buy any car for cash: pounds 750, he told me on the phone, so I towed it round.

When I arrived, he performed that neat trick essential to any Grant, Phil or Frank Butcher: he opened the bonnet and sucked through his teeth at the same time. I had not told him, he said, that the thing was a complete wreck; pounds 450 was the best he could do.

Clearly this was absurd for a modern classic but, as he jovially pointed out, the alternative was to tow it home.

We went into his subterranean lair for the hand-over of papers. He pulled a large roll of notes from his pocket (all East End business is conducted in wads) and proceeded to slap fifties on to the gleaming bonnet of a Jensen Interceptor. Now that, I remarked, was a decent set of wheels. 'Yeah,' he said, licking his oil-stained forefinger and peeling the last note from his wad. 'Worth 12 grand. Bought it off some geezer for pounds 1,200. Did I see him coming]'

In the soap opera, the north of Albert Square opens into a small street market, with the Vic on the corner. Mr Harris's architectural model for this was Broadway Market, to be found about a mile from Fassett Square across Martin Amis's favourite park, London Fields.

Broadway has recently undergone a facelift, its ageing cobbles replaced by herring-boned heritage bricks which, a couple of days after they appeared, were dug up by the gas board. But such gentrification has not disguised how depressed the street is.

Most of its shops are boarded up and bear optimistic 'All inquiries . . .' signs covered with Kurdish revolutionary graffiti. The two most patronised premises are the post office and the spanking new health centre.

All the elements reproduced on the EastEnders set can be seen, however: the Sunnyside Cafe, a ringer for Kath's Bridge Cafe; a launderette without, sad to say, a Dot Cotton to do your service wash; and the market stalls on the roadside, whose every detail has been copied, even to the colour of their canopies.

'We go out to East End markets all the time,' Mr Callan said. 'That was where we got the idea for Sanjay's clothes stall, and the luggage stall made its first appearance.'

As yet they have not reproduced Broadway's pet supplies stall, supplier of Madonna-style fright collars to the local muscle dogs. Nor, though the exteriors are identical, have they attempted the television-obsessed interior of the Cat and Mutton pub.

'One of the most frequent complaints we get about the set is that there aren't any satellite dishes,' said Mr Callan. 'Well, obviously the BBC couldn't have satellite dishes. But we've got an answer to that. We just write back and tell them that Walford's been cabled.'

(Photographs omitted)