On the thoroughfare for invasions, Nord-Pas de Calais has, for a long time, been centre stage for so many conflicts. Over the centuries, its towns were given walls in order to defend themselves. During the reign of Louis XIV these defences were perfected by Vauban with his famous ‘pré carré’. Today, Nord-Pas de Calais’ walled towns are a chance to travel back in time. Enjoy a historical, cultural and scenic tour of these open air museums.