Paris south of the Seine is changing rapidly, increasingly the preserve of those excited by Cartier or Armani rather than by the deeper cultural legacy of the French capital. However, it is a segment of the city which has acquired a unique blend of intellectual brilliance from the presence of the Sorbonne and the elite Grands Ecoles, together with an astonishing concentration of the studios - ateliers - and salons of those at the forefront of cultural innovation. Cubism, Surrealism, Existentialism and the theatre of the absurd all found their roots here. Saint-Germain may have lost much of this vitality, yet it survives in Montparnasse and in the more frayed edges of the 14th arrondissement, with vivid traces of the shifting cultural and artistic history of Paris.

This is a quarter offering exciting opportunities to see where ground-breaking artists worked and lived. Most intriguing is “La Ruche” - the beehive - a wine pavilion designed by Gustave Eiffel for the l900 Paris Trade Fair. It was moved to 2, passage de Dantzig, not far from the new Parc Georges Brassens, and used as studios by 140 artists, including Soutine, Chagall, Brancusi and Leger. Despite the “chien lunatique” sign on the gardienne’s door, it’s a lovely spot to visit, still occupied by working artist and potters. Mosaics and formidable lumps of sculptors’ stone fill the shaded garden.

The atelier of Russian emigre sculptor Ossip Zadkine has been transformed into one of the best little museums in Paris at ll0 bis, rue d’Assas. The gardens and workshop burst with sculptures in wood, stone, concrete and terracotta, fashioned by Zadkine with hammer and saw. A statue of Van Gogh dominates the collection. The quiet, cobbled impasse of the Villa Seurat was home and workplace to Dali, Henry Miller and Lawrence Durrell, and round the corner at 53, square du Montsouris there is a splendid example of Twenties modernist architecture - Le Corbusier’s studio for Amedee Ozenfant, designer of the Hispano Suiza car.

A plaque on Gertrude Stein’s former apartment at 27, rue de Fleurus records the large number of artists and writers she received here between 1903 and 1938 in a salon crammed with the works of Picasso, Cezanne and Matisse. Yet it was the magnificent but now pricey brasseries of the Boulevard du Montparnasse that were the most important focus for conviviality between the famous and the talented. Simone de Beauvoir was born over “La Rotonde”, Sartre was attracted by the seafood at “Le Dome” while “La Closerie Lilas” was the haunt of Lenin, Alfred Jarry, Picasso, Hemingway and is, still, of Charles Trenet.

Peter Lennon captured the key role of the bar in the cultural interchange of Montparnasse in his excellent Foreign Correspondent: Paris in the Sixties (Picador). He talks of a visit to the Falstaff Bar at 42, rue de Montparnasse with Eug ne Ionesco, where they found Jean-Luc Godard, Samuel Beckett already drinking and Sartre with what he liked to refer to as one of his “contingent” girl friends. Lennon describes this as “probably one of the greatest concentrations of talent per square foot Paris had ever seen, outside the cemetery of P re Lachaise”. The Falstaff is still there, surrounded by Breton creperies and Belgian brasseries, offering a choice of 50 Belgian beers and good-value moules et frites.

The building of the customs barrier, the Mur des Fermiers Generaux, in 1784 had enabled Montparnasse to become a “lieux de plaisir” offering cheaper wine and food than inner Paris. A rash of dance halls -“guinguettes” - cafes and theatres grew up; the rue de la Gate near the station preserves this demi-mondaine character with its sex cinemas and popular theatres such as the lovely Theatre de Montparnasse with its original 1880s decor.

There are powerful political associations with this corner of Paris. Russian exiles were so common in the early part of the century that a branch of the Tsarist police was set up to keep an eye on them. Trotsky lived in the rue de la Gate, and between l909 and 1912 Lenin occupied a tiny apartment at 4, rue Marie-Rose with Krupskaya and his mother-in-law, using it as a base to cycle to the Biblioth que Nationale to do his writing. The interior has been reconstructed into a small museum, financed by the French Communist Party.

The Maison de Lenine is one of the few remaining shrines to the kind of airbrushed history seen all over Eastern Europe before 1989, with a guidebook printed with touching shoddiness by Novosti Press in Moscow in 1976. Ho Chi Minh is said to have worked as a cook in the restaurant Le Polidor at 41, rue Monsieur le Prince, which, political connections or not, still offers cheap menus amid authentic turn-of-the-century decor.

The most durable memorial to those associated with Montparnasse is the fascinating cemetery on the Boulevard Edgar-Quinet. Sartre and de Beauvoir lie together in a plain grave, topped with pebbles. Tristan Tzara and Man Ray represent the Dadaists and Surrealists, Samuel Beckett and Eug ne Ionesco the theatre. Serge Gainsbourg and Jacques Demy found their last resting place here and, hidden among the tombs, is the family of Jean Sablon, singer of J’attendrai, perhaps the most evocative of all French popular songs. The graves of nearly 100 artists, scientists, writers and entertainers are plotted on free maps available at the poste de garde near the main entrance.

To book visits to the Maison de Lenine, tel: 42 79 99 58.

Group tours to the Montparnasse cemetery: tel: 44 10 86 50.

On y Va: French Culture Since 1945, edited by Malcolm Cook, is an excellent guide to the shifts and trends in French post-war culture (Longman)