This article examines the case of the town of Nouadhibou in Mauritania, a place of transit for African migrants heading for Europe. It brings a singularly fresh analysis of these migrations, as many other studies focus exclusively on the points of departure and arrival or, in other terms, African and European countries respectively. It not only shows the huge economic impact that this transit has had on the town, but also how tighter controls on migration have reduced the migratory flows and dried up the source of relative prosperity ? a blow from which Nouadhibou has not yet recovered. Nouadhibou, now a center for all sorts of trafficking, has become a "downgraded" town, with its title of economic capital no more than a reference to the past. The town now seems to have turned in on itself and on the meager remnants of wealth that remain.