Rough diamond on a choppy Med

"Rome by the sea", is how a Marseilles friend describes her city, ironically, as if to say we've got the hills, but not much else. This is the Marseilles way. The locals see themselves as rough diamonds - to trumpet their city would be deemed effete. Still, the low-key approach is hardly cause for complaint; it's part of Marseilles' charm.

I'd found a hotel in the Old Port, Marseilles' heart. Salty by tradition, the area is under gentle transformation. The Old Port's fabled character remains, however. When I tell the manager that my phone doesn't work, he wonders, with a shrug, if I can shout.

Clustered around the Old Fort, central Marseilles could be involved in a great urban experiment - an attempt to fit as many facets of city life in as small an area as possible. Stendhal, writing in the 1830s, claimed husbands were seldom cuckolded in Marseilles because it was difficult to stray without being seen or heard. Marseilles is still as compact, if not, perhaps, as well behaved.

In spite of the limited space, areas seem to be clearly defined. Turning into the rue St Ferrol, a couple of hundred yards east of the port, is like entering an ornately decorated catwalk. Its imperial architecture is set off by a string of designer shops, in and out of which parade Marseilles' beautiful people.

Across the road is Belsunce, home to many of the city's poor, and a favourite haunt of Marseilles' prostitutes. "La Marseillaise" was first sung in Belsunce; anti-Fascist Italians made it their base in the Thirties, and now it is the Little Maghreb. Belsunce has absorbed plenty of history, and it shows; even its buildings appear to sag.

The road separating the rue St Ferrol from Belsunce, the Canebire, Marseilles' main drag, has long been considered the divide between the "good" and "bad" parts of town. A little gentrification - the odd fashionable restaurant - has blurred the differences slightly, but the divide still holds. However, if you don't behave like the locals, and do move about, zigzagging across the Canebire, central Marseilles becomes a richly varied place. In Belsunce bars, you can hear, live and taped, some uncanny world music hybrids, born of north Africa and western pop.

A surprise, when you wander beyond this rumbustious centre, is that parts of Marseilles have the aspect of a village. Self-contained communities seem to flourish alongside the workings of the big city. Coming across the vallon des Auffes, just south of the Old Port - its few stone houses and bar slouching around a peaceful inlet - you'd swear it was a rural fishing village transplanted into the middle of the city, perhaps the work of a local megalomaniac.

Instead, the vallon is one of the villages that originally formed Marseilles. Drive along the coast road and you don't see anything of it, while from down below, in the vallon, you can faintly hear the traffic rushing by, but only see some old fishermen tending to their nets.

To reach another of the original villages, you need only regain the coast road and travel north of the Old Fort to L'Estaque, a good deal livelier than the vallon and one of the key sites of modern painting. Czanne worked and lived in a local squares and it was in a L'Estaque street that Braque devised Cubism. From 1860 to 1920 it was the place to be if you held a brush: Renoir and Dufy were among the many who came and painted what they saw.

But when you arrive - you can catch the number 35 bus from the Old Fort - there are no obvious signs of a celebrated past. There don't seem to be any streets named after painters, nor shops selling Impressionist teacloths. Instead L'Estaque seems happily carefree about its place in art history. It is where working-class marseillais come to enjoy themselves and the sea-front is packed with busy bars and restaurants. The preferred way of paying respect to the past is simply to revel in the bay setting and light that drew the artists to L'Estaque.

The painters established themselves in the hills up behind the coast road. The danger if you're playing the art pilgrim is that you have to pass the hedonists' seafront and its temptations first. Less of a danger, more of a tender trap,L'Estaque's row of friendly restaurants boast good, simple food and fine, local wine.

Even the most committed art pilgrim has time to linger. The place de L'Eglise, where Czanne lived, off and on, in the 1870s, is only five minutes walk up one of the narrow streets that leaves the front. Very quiet and still, the square looks out on to a cluster of pitched, tiled roofs and the sea

On the hill, little appears to have changed this century. In the Muse Cantini, in central Marseilles, hangs Braque's Maisons L'Estaque, the first Cubist work. The houses featured in the painting still stand, in the vallon des Rieux, 10 minutes' walk from the place de I'Eglise.

The bus journey back to town runs alongside Marseilles' long stretch of working port. The line of warehouses is rather elegant, and part of the fun is finding "sights" within a working city.

The last stop before the bus arrives back at the Old Port is for Le Panier, a second celebrated hillside community and Marseilles at its most historic, with few buildings dating from later than the 18th century. I approached via the monte des Accoules. This steep street is an obvious tourist alley; locals stand in doorways watching visitors as they puff up the hill.

The climb levels off near the picturesque but faded place des Moulins; its pretty fountain is dry and its paving stones well worn. As you move away from the place des Moulins, you are faced with a choice of alleyways and the area becomes a maze.

The locals are quick to help, and tend to assume you're looking for the Vieille Charit. This arts and science centre is Le Panier's star attraction - something of a symbol of the city getting back on its feet.

In dazzling pink and white stone, its four elegant wings enclose a courtyard and domed chapel. Inside, all manner of funky institutions are housed, including the grandly named Mediterranean Institute of Research and Creation. ("What goes on in there?" I ask an assistant. She stretches her arms wide, which means "lots of things" - or that she's not telling.)

Beyond the cultural powerhouse of the Vieille Charit, Le Panier has very much the feel of a tight-knit community: at the bar-restaurant O'Berry none of the other customers need to tell the waiter what they want.

Coming down from the narrow streets of Le Panier to the relatively large open spaces of the Old Fort's quays, you suddenly realise the relief the sea provides for a city as closely packed as Marseilles.

The boat trip out to the Chteau d'If, the infamous ex-prison which, legend has it, once held the Man In The Iron Mask, is Marseilles' big draw. The chteau has few charms, but the boat trip makes for a sharp refresher. Out at sea, the views of Marseilles are superb.

It's a short journey to If. But with the wind rising - the mistral, makes itself felt for a hundred or so days each year - and the sea choppy, it's long enough. By the return journey, the sea has begun to dance, babies are crying, and the 15 minutes to the Old Port last an age.

Later that night, a bar-room philosopher claims the mistral has something to do with the no-frills Marseilles character. It's difficult to stand on ceremony, he reckons, when any moment you could be blown over.

F A C T F I L E

Getting there: British Airways (0345 222111) flies three times daily from Gatwick, and Air France (0181-742 6600) once daily from Heathrow, to Marseilles. The lowest economy fares are identical: £153 midweek, £170 weekend, with a minimum stay of one Saturday night. Note that the BA flight must be booked by 2 March to qualify for this fare. For slightly less, Air France Holidays (0181-742 3377) offers weekend breaks in Marseilles, including flights from London and two nights B&B in a two-star hotel, for £146.

Further information: French Government Tourist Office, 178 Piccadilly, London W1V 0AL; 0891 244123 (a premium-rate service); fax 0171-493 6594.