Why go now? The immediate answer is: because there's a new, direct Eurostar service from London to Aix starting on May 4 for a two-month trial period. Another rapid answer would be: to see Nicolas Froment's 15th-century Burning Bush triptych, one of the French south's finest art-works, now restored to Aix's St Sauveur cathedral.

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The longer answer would be that Aix, the brainiest city in France, is particularly admirable in spring. One can sense life surging back along its sinews. Light and warmth will likely be unambiguous. The gardens (there are lots) are getting jollier, the fountains sparklier and café terraces on the Cours Mirabeau are filling up with students, jurists, fellows with red spectacles and floppy hair, and very smart women.

Aix has been a cultured, high-IQ sort of spot since Good King René had it as his 15th-century Provençal capital, bringing in artists, lawyers and nobles. They've kept on coming. Zola spent his youth in Aix as, more noticeably, did Paul Cézanne, a local lad. The Mazarin district has aristocratic town-houses by the discreet street-full. One of Europe's greatest opera festivals is a summer fixture.

The rest of France - notably the neighbours down the road in Marseille - thinks the city very far up itself, in a haut-bourgeois sort of way. But that's wrong. The elegance is, after all, southern, underpinned by Latin rhythms coursing through narrow streets, grand squares and an entire civilisation of bars and restaurants. The pulse can easily quicken - and then, when you stumble out of the rock'n'blues Scat Club at 4am, stop altogether.

Getting there

The direct St Pancras-Aix TGV runs Saturdays, from May 4-June 29, taking 6h15 outwards and half an hour longer, inwards. Passport requirements at Lille add the extra minutes. From £109 return (08432 186186; eurostar.com). Otherwise, nearest airport is Marseille, a 30-minute shuttle bus ride from Aix, £6.50 one way. British Airways (0844 493 0787; ba.com) flies there from Heathrow, and EasyJet from Gatwick, (0905 821 8905; easyjet.com), year round. EasyJet resumes flights from Bristol on June 22. Ryanair (0871 246 0000; ryanair.com) wings over from Stansted year round, from East Midlands from March 24, and from Edinburgh from April 2.

Where to stay

Special treat

If Marie Antoinette were to return as First Lady of France (the signs are that she has), and were she then to travel to Aix, the Villa Gallici (number 1 on map, above; pictured below) is where she'd stay. It has the required 18th-century country-house sumptuousness, 21st-century five-star standards and let-them-eat-brioche exclusivity (0033 442 232923; villagallici.com; doubles from £192, then rising sharply).

Mid-range

Aix is thick with almost-in-town country houses. The Pavillon de la Torse B&B (2) occupies a smaller, more homely version - for those, perhaps, on the fringes of the royal court. Traditional bedrooms are nevertheless plump with comfort and taste, the gardens are courtly, and the hosts mingle with guests during a free drinks of an evening. This is as noble as most people need (0033 950 584996; latorse.com; b&b doubles from £108).

On a budget

And for those of all classes who simply want a cheaper (if smaller) bedroom, there is the Hotel Le Mozart (3) - modern, practical two-star whose warmth of welcome will send happily off exploring Aix (0033 442 216286; hotelmozart.fr; doubles from £63).

On arrival

4pm: Stroll the Cours Mirabeau, from the vast Rotonde roundabout (pictured below) and fountain at the bottom (the figures on the fountain represent Justice, Fine Arts and Agriculture, as you'd expect). The broad acres of southern France's stateliest avenue are lined with phalanxes of plane trees, dotted with more fountains and edged with classical town-houses which have known their share of scandal. The Cours is the heart of both the city and its self-image - grandiose, graceful and spiced with civilised café life.

5.30pm: Talking of which, pop in for an early sharpener at the Café de Deux Garçons (4) (53 Cours Mirabeau). Insist on your order, or the waiters will ignore you, as they've ignored everybody since this was Cézanne's local. If he wasn't dead, he'd still be waiting for his second absinthe. His dad's hat shop was next door, at N°55.

6.30pm: Take the nearby Passage Agard through to the Place Verdun (5), and thence into the medievalo-Renaissance old town. We'll be returning here tomorrow. Tonight's job is to find a decent apéritif. The bars on Rue Verrerie beckon.

8pm: Weave your way through the streets to Rue Rifle-Rafle. Hidden down there at N°8, Le Millefeuille has a decent terrace, intimiste décor and a jazz-enthusiast chef who improvises with whatever's come in from the market (0033 442 965517; mains from £19). 11pm: If you're still standing, try the Scat Club (11 Rue Verrerie; 0442 230023).

Rock, blues or electro - the place has it all, and releases you only when you're fit to drop.

Day one

9am: Back to the old centre, whose scurrying streets squeeze the populace out into ancient squares colonised, on Tuesdays, Thursdays and Saturdays by Provence's finest market. You'll find convent-raised poultry, cleavered by nuns, Lynyrd Skynyrd LPs and sensuous abundance in between.

9.30am: From the town hall square, with its 16th-century clock tower (pictured below), head up Rue Gaston Saporta. Ornate town-houses press in, boasting of Renaissance wealth and then you're at the Archbishop's Palace, nerve-centre of Aix's Opera Festival. Don Giovanni and Rigoletto head a packed programme this year (July 4-27; festival- aix.com). Just beyond, St Sauveur cathedral features an amalgam of architecture from the fifth to 17th-centuries. Somehow, it's all harmonious. Note particularly the cloisters, and Froment's magisterial triptych.

10.30pm: Coffee at the nearby Archevêché Brasserie (6) (36, Rue Gaston Saporta) before crossing the boulevard to Avenue Cézanne and a brisk walk up to the Atelier de Cézanne (0033 442 210653; atelier-cezanne.com). The artist's last studio – where he completed Jardinier Vallier and his final Grandes Baigneuses, while also chasing his obsession with Aix's Mont Sainte Victoire - has been left as if he'd just popped out for tobacco. His beret and bowler hat, paint-spattered smock and still-life clutter are all in place. One can almost, but not quite, sense his presence.

12.30pm: Return to the centre for lunch on the Forum des Cardeurs (7) by the town hall. The square groans with restaurants. Try Le Coquet at N°2 (0442 234621; two- course lunch £13.50) or, if you wish to spend more, the tiny Epicurien at N°13 (0689 334983; two-course lunch £20).

2.30pm: Two choices this afternoon. If you need more Cézanne, bus out (N°2B), from the Rotonde) to the Jas de Bouffan (pictured below), the family mini-mansion where the young Cézanne began to re-define painting. The chestnut trees featured in the Allée des Marronniers are still there, if a little battered, and now encircled by high-rises.

Then take another bus (N°6) to the Bibémus Quarry, whose unruly rock and trees provided the inspiration edging Cezanne towards cubism. Reproductions of works at the point where he painted them pepper the quarry. You'll need walking shoes, mind. To visit both, and the Atelier, buy a £10 ticket covering all three, from the tourist office (300 Avenue Guisepppe Verdi; 0033 442 161161; aixenprovencetourisme.com).

Or, for more harrowing moments, make for the Camp des Milles. Just out of town, the ex-tile works was southern France's major internment and deportation centre during the last war. Restored for £16 million, the enormous site opened last year as a memorial-cum-museum. The content - putting the camp in its context - is first-rate and the emotional punch debilitating. Take the 10-minute bus ride from La Rotonde (stop: Gare des Milles). Allow three hours (0033 442 391711; campdesmilles.org; £8).

8pm: Apértifs at the chic, funky, cocktail-laden La Rotonde (8) (it's also the name of a bar at 20 Place Jeanne-d'Arc ; (0442 916170; larotonde-aix.com) before dinner in the vaulted cellars of Le Formal (9). Jean-Luc Le Formal's place defies the rule stating one should never eat in a restaurant bearing the chef's name. His is among the most inventive cooking in town (32 Rue Espariat; 0033 442 270831; restaurant- leformal.com; menus from £33).

Day two

9.30am: Saunter to the Musée Granet (10) (it opens at 10am), Aix's main gallery (Place St Jean de Malte; 0033 442 528832; museegranet-aixenprovence.fr; £3.50). If it's a bit light on paintings by Cézanne, that's because, back then, the curator, in common with most of Aix high-society, took against the mould-breaking artist. Provincial towns generally do. "Never in my lifetime will one of his works enter here," said curator Pontier in 1896. None did, though some have crept in since, and there's a wealth of other good stuff. Best of all, though, will Grand Atelier du Midi summer show. From Cézanne to Matisse showcases Med-inspired art from 1880-1960: June 13-October 13.

11.30am: The Granet is in the Mazarin district, which you should now wander, wondering at the wealth and self-importance behind all those 17th and 18th-century town-houses. Their monumental stones betoken power and respectability, but still conceal more than they reveal.

12.30pm: Last lunch on the Cours Mirabeau, on the terrace of the Bastide du Cours, (43 Cours Mirabeau; 0033 442 261026; bastideducours.com; two-course lunch £17) to relish the bustling serenity of Aix life and some acceptable Provençal cooking.

Read our full expert guide to Provence at telegraph.co.uk/travel/destinations