There can be few routes through France which have not been exhaustively charted by travel writers. There's one, however, which runs for fifty kilometres through picturesque-sounding towns like Aubervilliers, Blanc Mesnil and Gif-sur-Yvette. But there are no chateaux here, no charming little relais routiers, and absolutely no tourists. Because these are the Paris suburbs, thirty-eight stops on the express subway, the RIR, recalled by most visitors only as a graffitied blur on their way from Roissy airport.

Accompanied by the photographer Anaik Frantz, ex-publisher and novelist Francois Maspero embarked on a tourney of discovery into a terrain vague with ten million inhabitants, a radical past - the 'red suburbs' - and a tense present. The result is this unusual and fascinating book, a vivid mixture of diary, ethnology, history and politics.

At each stop the travellers got off the train, hunted for a room and a meal, and lost themselves in the desolation of billboards, superstores and flyovers, or the uniform comforts of Novotels and solar-heated pavilions. This is a world where names don't make sense, where immigrants from Burkina Faso live in run-down tower blocks called Debussy on the avenue Karl Marx, their kids dodging the police between the lycée Jules Vallès and the Yuri Gagarin youth club. A world haunted by memories, glorious and monstrous: the Commune, the Popular Front, or the camp at Drancy from where French officials sent a hundred thousand Jews to Auschwitz. A world where no one's a racist but ..., and National Front posters are everywhere, as menacing as the ubiquitous guard dogs.

Maspero's aim is to put this world back on the map, and he does so with self-effacing humour, genial erudition and unwavering solidarity, helped by Frantz's rare ability to take photos which are both candid and respectful. This is an inspiring record, proof that a month on the RER can teach one more about la France profonde than a year in Provence.

Translated by: Paul Jones