If Paris can turn a disused train station into a world-class museum (the Musée d'Orsay), why not transform an art deco municipal swimming pool (built 1927-32) – an architectural masterpiece inspired by civic pride and hygienic high-mindedness – into a temple of the arts? This innovative museum, 12km northeast of Gare Lille-Europe in Roubaix, showcases fine arts, applied arts and sculpture in a delightfully watery environment.