As early as the 1970s, whilst French Communes were declining due to the steel industry crisis, Luxembourg has implemented a national program of redevelopment for its steel production area. Now, the urban project designed for the Belval-Ouest derelict lands brings a new impulse to the Southern area around Esch-sur-Alzette, next to the French border. The cross-border travel-to-work area of Esch-sur-Alzette Villerupt Audun-le-Tiche, as it is shown by the increasing number of cross-border workers from Lorraine, is more and more attracted by the strength of the polarization from Luxembourg. The urban ambitions of the Belval project have stimulated the cross-border cooperation stakes appeared in governance and in sustainable development of the cross-border area, a challenge partially determined by the future of its derelict lands.