TRAVEL; When the past is another city

I HAVE been travelling with an old whore, which is bizarre and exhausting but not at all like it sounds. It means the usual round of airports, passports and hotels, but it also means imagining; because I found this woman in the Manhattan court records of the middle of the 17th century, when New York was still the Dutch colony of New Amsterdam.

She was written down as a few fines, a few court judgements, and the occasional memorable quote ("I want to be the people's whore!"): a woman called Gretje Reyniers. She was obviously, gloriously, her own woman, the very first of the long line of whores of New York. I fell for her. I wanted to tell her story, but since there wasn't enough evidence for a memoir, I had to imagine her world.

That is where the travel began. It wasn't just a question of going from place to place, but a deliberate attempt to enter another time. I was looking for clues to the life of a woman who wasn't anybody in particular, but who lived in a golden trading town like Amsterdam and then in an empty, God-forsaken place like New Netherland (the old Dutch colony on the Hudson River now split into New York and New Jersey). I started, of course, in libraries and archives where the written record survives. But after a while it was time to go to the places she knew - if I could. I discovered abruptly the complications of time travel.

It sounds mundane enough. We visit historical sites, go to places where so many things about life haven't changed a bit - ox-ploughs biting up the earth, say, or women in long black dresses - that we vaguely sense we've gone back in time. We look at buildings where the order of the stones hasn't changed much in 400 or 900 years.

But suppose you want to do more; you want to chase one particular ghost through the history of a city. In New York, it's almost impossible. Even the island of Manhattan has filled out since Gretje's day, so that the old waterfront is now a few blocks inland. The water itself is different - there used to be oysters in the harbour - and so are the plants and trees; the very weeds are "exotics". It has become shocking to hear something that has survived - as once I heard the geese flying south in winter, heard the song of their wings on a quiet street just off Fifth Avenue.

Besides, everyone knows New York gets torn down and built up on a regular basis - or moved. For there is a tiny blue-and-white clapboard house on a Greenwich Village street that looks the essence of the old Village - until you realise it was moved there bodily on a truck from the East Seventies. Wall Street is a canyon, where once it was a wall of sods and rope and sticks. The Bowery once meant "farmland". But there is no such clue in the names of New Amsterdam's canals, Herengracht and Prinsengracht. They were actually one tidal ditch that was given two names because of a bend - a ditch that alternately flooded and stank, or drained and stank.

Back in the Old World, Amster-dam itself - the town where Gretje started - looks reliably antique on the postcards: all those fine gables with the right dates, the back alleys with tall garden gates, the houses that lean forward so you can winch the furniture in through the windows, whose rooms go off at diagonals to make room for their neighbours. You'd think you could trust what you see.

You amble along a raucous street of leather bars, sex shops, budget hotels, and try to imagine when this same narrow way - Warmoesstraat - was the city's Gold Coast, a street of rich traders in fish and grain who sold from the front and took delivery from the harbour at their backs. The water's still there, at least. You try to subtract all the street life from the street, put the neon out of your mind, then put back the people who walked there almost 400 years ago: another kind of street life, maybe with as many hustlers but with very different tricks (no latex, for a start).

There are houses dated in the 1640s - the Dutch liked to date everything - but they are apartments now, and in the basement are bars with the palm- tree signs that mean dope is sold there. Some of these streets used to be canals. The change of use makes you less aware of how people used to live there: with the peat and sea coal stashed in the attic, the great windows on to parlours that passers-by were meant to see because all those riches meant the owner had God's favour. You have to add back the towpath horses, the lighters shifting goods along the canals, and the winches ready to swing the goods up to attic stores - to make the canalsides useful, not just pretty.

Oddly, it's easier to understand these streets when they're interrupted: a bit of grey and yellow art deco here, a bit of 19th-century historicism there, the occasional fat bank building that sits down suddenly like a bully. At least that shows how the use has changed along with the smells, the very nature of the place. Where there's nothing to alert you, you can miss the whole logic of the city. Take the Nieuwandijk, a tacky sort of mall with everything from C&A to pancake stands, to raucous leather shops; it's actually the city's second-oldest place of business.

Indeed, the very best-kept remains can get in the way of imagining the past for yourself. You enter a monument, a bit of national heritage, and you're expected to read it like a book in the order prescribed. Even if you manage to miss the gift shop, the tea room, the audio tour, there are fundamental problems: churches that aren't always for the awkward business of prayer (the Nieuwe Kerk on Dam Square, for example, is for exhibitions); castles that aren't for defence (Nijenrode, a few miles up the Vecht river, is a business school); palaces that aren't for some show-off elite (unless you count the curators). The art gets lodged in special rooms, with things to read on the wall.

Sometimes it seemed I was closest to the 17th century when eating herring in the street, an old Dutch habit, or standing in the sweet spice smell wafting from a bakery; Amsterdam used to smell this way when it didn't smell of the shit in the canals, or the whale-oil stores, because the East India Company deliberately burnt up all their nutmeg and cinnamon to keep those spices pricey.

I learnt to start with small details. Look at the late 17th-century dolls' houses in the Rijksmuseum, for instance, and you have a clue to how these great merchant houses worked: who slept where, who worked where. Then find, in the middle of the sleaze of the red-light district, the Amstel- kring Museum (on Oudezijds Voor-burgwal) - three merchant houses, built around 1660, with a splendid Catholic church in the communal attic. As long as nobody could tell from the street what it was, the church was safe. It is lovely; there are rooms hung with museum shows, but more remarkable are those that have been kept much as they once were.

There's a parlour, dark and warm, with all the closed-off certainties of a prosperous family; and a tiled kitchen down vertiginous stairs, with an open fire, a scullery, a commode in the scullery. Above, there's a bedroom whose windows give out eccentrically on to a landing, not the light of outside. It's known as the priest's room, but in a whole building honouring the Church, it's curious that the priest was tucked away in such a short box of a bed, in a room without air or privacy. A servant - like Gretje - seems a much more likely tenant.

If you want clues to a grander style of life, try the Theatre Museum at 168 Herengracht. I went there because I needed to know how a theatre in Gretje's time managed special effects - rain, lightning, thunder; there's an almost full-scale theatre that you can conduct like a megalomaniac, staging a whole vivid storm at sea. But the museum is itself an extraordinary, double-fronted 17th-century house. Behind the racks of mime memorabilia and stage frocks are glorious painted walls. The ceilings are delicately moulded; at the back is a garden with magnolias.

Or there is Rembrandt's House on the Jodenbreestraat, which houses almost all his etchings. After you've been dazzled by the pictures, imagine the house as it was; life lived on the lowest floor, the studio above, and above that an attic for a few students. The place turned out to be too ambitious for Rembrandt, and pushed him into bankruptcy; it was an aspiration more than a home. It's almost safer to think of it as a museum.

What has gone for ever is the street life; to imagine that you need second- or third-rate paintings, the details in their corners above all. The Amster-dam Historical Museum (set in a 17th-century orphanage at 92 Kalver- straat) has many that aren't masterpieces; they're tricky to read under their dark varnish, but a source of extraordinary information. Here's the Haarlemerpoort gate, where the tarts used to do their business, as it was in 1615 - when windmills lined the city walls. Here's the Dam Square in 1604, the last time the lepers came begging, with a man selling lottery tickets for the madhouse with pin-ups of the half-bare mad. There's a gin-seller, a rat catcher and a wheelbarrow full of cheese. You can see stiff black lines of civic guards on parade, and the bears and tumblers and beery couples at a fair. You can see the Old Town Hall with its arcades, and the Old Town Hall burning down.

The pictures open up the past - of work, of the street, of people having a good time without being allegorical about it. You can tell how to cut up a fish, and how the grand fleets looked when they came into the harbour. You can also pick up the complacency of the civic guards, the bloodless exhaustion on the faces of some of the women traders, the games children played. The museum's own displays add to the details - how pewter was made, or the black faces with lolling tongues that advertised shops.

When you walk back into the city, there is less of a screen between you and the past. You catch the gun barrels on the pediment of some grand house, and spot where gunmakers lived. You can imagine the walls that ran out from the church-like gate that still stands in the Nieuwmarkt. On the mildly seedy Damrak, you can look out on the water and imagine sailing ships racked up together, not tourist boats. You can demolish the Central Station, if you want, and put the old harbour in its place.

I had to use my imagination, in the end, to remake the world of my particular ghost. But on the way I saw Amsterdam as I couldn't have seen it before - as one age traced over another. I ended up grateful to be travelling with an old whore.

! 'The Story of the First Whore of New York' by Michael Pye is published on 25 May by Granta Books at pounds 13.99

GETTING THERE: Campus Travel (0171-730 3402) has flights to Amster- dam for pounds 89, or pounds 69 for students. Flightfile (0171-3231515) does flights from pounds 78. You can go by coach for pounds 44 return with National Express (0171- 730 0202) or Eurolines (01582 404511). All flights subject to pounds 7.40 tax.

WEEKEND BREAKS: Kirker Travel (0171-231 3333) offers two nights in a superior two-star hotel for pounds 195, inclu-ding car transfer to hotel and rail ticket to airport when leaving, b&b, and canal cruise. Lupus Travel (0171-306 3000) has two-night breaks for pounds 154, b&b in a two-star hotel in the centre.

FURTHER INFORMATION: Dutch Tourist Office, 25-28 Buckingham Gate, London SW1E 6LD (0891 200277: recorded message charged at 39p cheap rate, 49p peak rate).