It is ad 100. Boom-town Londinium, capital of Rome’s newest province, is expanding rapidly. As grand civic structures such as the amphitheatre and fortress are being built to last, so a warren of smaller domestic buildings springs up along the main route, the Via Decumana. It’s a lively, sprawling thoroughfare nestling in the valley of the Walbrook between Cornhill and Lud Hill, housing the merchants and craftsmen who have moved in from all corners of the Empire. Life may be short in Londinium (ending at around the age of 30) but it is full of promise. Having survived Boudicca’s bloody uprising in ad 60, the nerve centre of Roman expansion is jumping.

Cut to 1995-96. Beneath what is to be an imposing new office building at 1 Poultry, archaeologists (funded by developer Palumbo and English Heritage) uncover the Via Decumana of two millennia before. Under the shallow foundations of the last Victorian building in the City of London, they find organic material ranging from timber and leather to bones, seeds, pips and pots: enough to build a detailed picture of life back in ad 100. Removing the finds to the Museum of London, they begin to develop one of the best new exhibits in a museum today.

For the next six months, visitors will be able to time-travel. Each small group will walk through three buildings from the high street of the Roman city, to touch, feel, smell, hear and see Londinium. You catch glimpses of a video made with a Roman reconstruction group, hear the constant clatter of wheeled vehicles, the chatter of children and insistent noises of domestic animals, smell baking bread and less savoury odours from the running open drain.

Above all, you absorb the sense of living in basic conditions, with beaten earth floors, roughly plastered walls, and unfinished wooden timbers. It’s a far cry from the feel of most Roman exhibits, all togas and hypocausts (central heating). High Street Londinium offers a refreshing look into the life of the entrepreneurial up-and-coming middle classes of a provincial Roman city. Yet it is not primitive: amid the rather squalid conditions of the carpenter’s living space, someone found time to use bronze tweezers to smooth her eyebrows and raise a small shrine to the household gods.

First, visitors see a video which explains the process of building the exhibit, in which replica Roman tools were used. Throughout the summer, time travellers will also be able to catch craftsmen using such authentic tools as early potters’ wheels or mallets crudely hacked from the boughs of trees. The tour of the high street starts in the baker’s kitchen. Huge roughly hewn beams support a high ceiling, with a thin half-partition wall to separate the kitchen from a afe area which provides fast food at midday - lentil soup, bread and cheap wine - and board games for entertainment.

Pots, spoons and basic plates are lying around, in a space dimly lit by windows which are no more than holes in the wall.

Outside, a back yard in which ragged weeds sprout leads to the huge commercial bread ovens, built away from the house to limit the fire hazard.

Chickens and pigs were kept in the yard, fed on scraps until slaughtered for food.

Next door in the carpenter’s shop, with a beehive in the yard behind, a range of work is in progress from small items such as wood for writing tablets to big slats for house-building. The living room is a revelation.

Cooking took place on a fire set in a hole in the ground. A tiled hotplate near the fire held the dishes ready to serve. Smoke found its way up to the rafters. The family would have slept on straw mattresses unrolled by the fire, all in a space not bigger than five metres square. A pot served as a toilet, to be emptied in the drain.

The neighbouring merchant’s premises appears slightly grander. In the reconstruction, plaster has been smoothed, glazed green or red Samian ware pots are offered for sale, shelves hold exotic spices and a small pile of change together with scales and wax writing tablets speak of a good turnover from the shuttered shopfront. An oil-lamp, a well and a ladder to an upstairs living area speak of prosperity. Yet what is this? The back room is unfinished. It turns out we have shifted further back in time, to ad 60, and in an uncomfortable instant Boudicca’s army is about to hit town and wipe out this nice little earner with a raging fire. Life was not too stable, even under the Roman empire.

As you emerge from High Street Londinium, the real finds from the excavation are on display, with their eloquent evidence of vanished times.

How much more interesting they seem now that the visitor has a picture into which to slot them. Yes, one of the shops was destroyed by fire in about ad 60. Yes, we know that these small business owners kept bees, pigs and chickens and drank imported wine. Evidence was found of many writing tablets, of hairpins and brooches and gaming counters, and of systematic construction of houses. The Romans were in Britain and, Boudicca or not, they meant to stay. heir determination can still be sensed today, in the huge new buildings tanding on the old Via Decumana.

Victoria Neumark

Open Monday to Saturday, 10am to 5.50pm, Sunday noon to 5.50pm until January 7 2001. Under-16s and disabled visitors free, concessions pound;3, adults pound;5. Events programme available for groups. School parties can arrange for interpreters in character to accompany tours on 020 7814 5777.

Information line: 020 7600 3699