France Special: Take the plunge

An Art Deco swimming pool in Roubaix, praised as the most beautiful in France, has been transformed into an museum. Simon Calder dives in

How strange it must have been for the people of the north who grew up a couple of lifetimes ago, when the land began to mean less than machines. France is vast – twice the size of Britain. But the sun-bruised Basque has always been bound to the pale-cheeked citizen of "Le Nord" by agriculture. Cultivating fiery peppers in the foothills of the Pyrenees had a certain egalité with raising barley in the Flanders fields 1,000 kilometres away – until the mill machinery found its way across the Channel and moved into the windswept northern plains.

Compared with the rebellions that have torn through France, the industrial revolution was a relatively minor event rather than a social upheaval on the scale of that in Britain. Yet industrialisation brought prosperity to places where the prospects must previously have looked as bleak as the landscape.

A corner of French Flanders, wedged in by Belgium, built its fortune on cotton. Vast mills were created which made the north-east of France resemble the north-west of England. And at the bridge of the good ship enterprise was Roubaix.

Prosperity takes a while to decay. Rue Jean Baptiste Lebas forms a grand axis between the generous hôtel de ville (town hall) and a railway station that is several degrees too grand for its current branch-line status. Just along on the north side, the Grand Hôtel is so replete with air, graces and belle-époque ironwork that the sum total of the embellishment looks as if it could cause the hotel to overbalance and tumble into the wide road.

What might have stood on the other side of the rue? A mirror-laden couturier or – at the very least – a brass-heavy épicerie (grocery store) for the wives and daughters of the owners, perhaps. The demolition team arrived a few years ago. They created a gap like a missing tooth in the jaw of Roubaix. Beyond it, a random fragment of redbrick wall still stands – quite tall and wide, but with its wounds exposed, as if waiting to be discovered by location scouts for a war movie. And just beyond that is the swimming pool.

Roubaix enjoyed affluence long enough for the town to invest in "la plus belle piscine de France". It took five years from 1927 for Albert Baert to create a temple to the bather, endowing it with a railway terminus roof, and – at each end – golden glass which makes every moment sunrise in a part of France where summer is often glimpsed only in the Provencal produce at the market. This is, indeed, the loveliest swimming pool in France.

For a while, it seemed Baert's Art Deco masterpiece would follow the cotton trade into oblivion when Roubaix's bathing classes won a bigger, more modern piscine on the outskirts. Thankfully, it was rescued – and reinvented as a home to artistic celebrations of the human form, instead of le vrai homme, in the Musée d'Art et d'Industrie.

A shallow pool is all that remains, aquatically speaking. But Baert's beauty was not all washed away with the pool water. Traces of the original mosaics that led down to the deep end, and the porcelain shower cubicles that lined each side, have survived. They frame the ranks of sculptures that comprise a startling tableau – men and women, few dressed, with or without the usual number of limbs, in poses from pensive to pouting.

Hommes and dames are no longer strictly segregated. The spectacle that visitors create as they move around the frozen figures is a drama. So it takes time before your eye is drawn from the pool towards the other exhibits, which take a provincial attitude to art. Dolls here, swathes of fabric there – and, in the museum shop, hulks of boilers that once warmed the waters (not for sale). Late 19th-century engravings show the satanic scale of Roubaix's mills, stretching halfway to Calais. L'Enfer du Nord – the Hell of the North – is the name of the excruciatingly tough Paris to Roubaix cycle ride. But the term applied equally to the town's post-industrial decline.

The municipal mood has improved. Now and again a shard of sound effects elbows in, with the echoing laughter and screams of the Saturday morning schoolboys shattering the reflections of the few tourists who have made it here from the Eurostar station in Lille.

Anyone who reaches Lille Europe has no excuse for shunning Roubaix. You can choose between the fast, direct, brand-new tram line or the fast, direct, almost brand-new Métro to cover the 10 miles between the two places in speed and comfort.

Regional recuperation – partly generated by the Eurostar link, but mostly thanks to Eurocash – has been highly successful in Roubaix. But I wonder what they thought when Britain's biggest airport company called? Fortunately for the calm of this corner of France, BAA plc did not want to solve the south-east England runway crises by building a new airport here – it wanted its property subsidiary, McArthurGlen, to rejuvenate Roubaix's centre. The Grande Rue had degenerated into a retail muddle that even the pomposity of the fine Banque Nationale de Paris on the corner could not elevate. Whether turning the middle of town into a "Designer Outlet Village" is the optimal solution to urban blight is open to question, but for good clothes it's closer and cheaper than Paris. The irony is that these fabrics are almost all imported, while Roubaix returns to its roots in the Flanders fields.

"On ne triomphe de la nature qu'en lui obeissant," as Francis Bacon is quoted in the museum – "We can triumph over nature only by obeying her."

La Piscine Musée d'Art et d'Industrie (00 33 3 20 69 23 60) opens 11am-6pm from Tuesday to Thursday, 11am-8pm on Friday and 1-6pm at weekends. Admission €3 (£2).