Somerset Maugham famously described the Côte d'Azur as "a sunny place for shady people". Pale-skinned, eager, all too obviously new arrivals, we plunged into the warm sea on our first afternoon at Beaulieu and scrambled out as beachcombing thieves were helping themselves to our belongings.
Before us lay the glisteningCorniche de la Riviera, the greensilhouette of Cap Ferrat to one sideand Monaco's grandiose port on the other. Behind us Beaulieu's Rotonde, circular glass ceiling painted with sunflowers and chandeliers shimmering like fairy lights, dripped belle époque fantasy.
No shoreline in the world has so effectively been transformed from place to idea as the Côte d'Azur. Fifty years ago, when Graham Sutherland painted Maugham, perched on an exotic bamboo seat and basking in a sunburst yellow backcloth in Cap Ferrat, the portrait encapsulated the Riviera's chic allure for exiles from drab northern Europe.
Maugham bought Villa Blanche in Menton; his neighbours were Picasso in Mougins, Graham Greene in Antibes, Marc Chagall in Vence. The coast was developed, and more accessible than in the 18th century when the English writer Smollett spent 15 days and £120 (the equivalent of £13,000 now) travelling from London to Nice. Yet the era of Easyjet (£14.99 London to Nice) and Easycruise, the garish floating block of windowless cabins new to the sea this summer, could not have beenimagined.
Today, by contrast, the Côte d'Azur shows its divisions. We still see the sea and pines of St Tropez through Signac's frenzied dots and the cool, bright half-shuttered interiors of Nice through Matisse's luminous paintings. But the myth of high culture crossed withstunning natural beauty is buried beneath grid-locked traffic, sardine-packed beaches and a hinterland of sickly, peach-coloured bungalows crammed together on estates which are infinite construction sites. The democracy of travel has created two Côte d'Azurs: one is flash, hard, cheap, crowded and frenetically flourishing. The other is hidden, exclusive, thrives entirely on le snobbisme of culturalnostalgia and, faced with global tourism and France's aggressive policy of regional redevelopment, may notsurvive.
This is the past, another country, and for instant immersion we skipped airports and began at Le Train Bleu, the opulent restaurant at Paris's Gare de Lyon. It looks down on platformsof sleek TGVs but is otherwise unchanged, in its leather armchairs, white tablecloths, mahogany drinks bar and smart service, since its inauguration in 1901.
Forty large frescoes depicting sites along the old railway network south dominate walls and ceilings: Villefranche and Monaco by Frederic Montenard, pupil of Puvis de Chavannes, and Albert Maignan's Theatre at Orange in the dining room; Marseilles' old port and "Nice, the Battle of the Flowers", by Henri Gervex, a friend of Renoir, in the Gold Room. Fin de sièclecurves and pastel colours probably look better now than in the days of steam, when smoke fumes must have blackened the place. The food - foie gras salad, vacherin of tropical fruits - is rich and traditional while the TGV, which offers a first view of the Mediterranean at Marseilles, three hours after lunch in Paris, is the flagship for Europe's 21st century railway age.
The original Train Bleu, which gave the restaurant its name, was an over-night affair with scandalously interconnecting cabins known as the "train of paradise"; it inspired a Diaghilevballet, starring Bronislava Nijinska as tennis player heroine, with stagecurtain by Picasso and costumes by Coco Chanel. Diaghilev's Ballets Russes was a highlight of 1920s Monaco; for a performing arts spectacle today its closest descendent is the outrageously glamorous Azuriales Opera Festival, held each summer at Cap Ferrat's pink and white wedding-cake Villa Ephrussi. Built in the 1900s by Beatrice de Rothschild, who spent just six nights in it, its marble columns and frescoes recall a Venetian palazzo and in the grand, balconied hall, subtly played piano-accompanied opera is an intimate, dazzling experience. With an audience of 200 seated in the round, no intake of breath or stitch of gold thread on a costume goes unnoticed, psychology and character-acting is in-your-face emotional, and the effect is electrifying. It is a class act, much more than Glyndebourne-on-the-Med; I have never felt so intensely part of a Mozart opera as at the Azuriale's Magic Flute.
Outside, Rolls-Royces with Monaco plates lined the car park, diamonds were big and almost everyone except my husband and son, was in a white dinner jacket. Alas, our tickets turned out not to include the gala champagne reception, arranged in the lush themed gardens among fountains, grottos and rose groves looking on to the bay. Exiled to the beachside equivalent of Pizza Hut, we learnt the lesson of the rich: someone on the Côte d'Azur will always be more privileged than you are.
Matisse's Chapelle du Rosaire, its lemon and ultramarine stained glass so evocative of the Mediterranean light and sea, Chagall's Biblical Message museum in Cimiez, and the Fondation Maeght in the hills of St Paul, are France's three unmissable shrines to modernism. The Maeght, a dynamic white building, catching the limpidnatural light so brilliantly that it seems to expand on summer days, has a mosaic by Braque, Picasso prints, Chagall murals, Miro sculptures dotting the garden and a café whose spindly chairs and tables are designed by Giacometti. When you leave, follow the winding path into St Paul and look for a small gate in an old wall on the edge of the village and an unobtrusive sign showing a gold dove. This leads into the vine-glad, secret garden of the Colombe d'Or, the superb restaurant-hotel where Dufy, Leger, Cocteau and Co - all Côte d'Azur residents - used to pay their bills with paintings and sketches which now line the walls; a giant mobile by Alexander Calderpresides over the swimming pool.
We stayed yet further from the madding crowd, in an art deco villa once occupied by Edith Piaf, then by Georges Simenon, so hidden in the woods behind Mougins that, after we had turned several hairpin bends on a gravel drive, it surprised us like Sleeping Beauty's castle, suddenly emerging through mature olive trees, giant cypresses and an ancient rare black oak. A park of layered terraces, and verandas fringed with curtains inburnished gold - even for the bathroom - afforded grace, style and views to die for. Though too far away, we fantasised that we could follow the shoreline and pick out favourite landmarks. No distance, however, could screen out the noise of the autoroutes which ran beneath us, a labyrinth winding through pine-clad hills and illuminated at night by a stream of cars whose routes we traced from above like bright dots on a transistor circuit. Never stopping or silent, they were oddly comforting, a reminder that the Côte d'Azur is alive as well as being a museum.
Jackie Wullschlager is the FT's chief art critic
