On a slope in the valley of Boulzane at a height of 697m, the outline of Puilaurens Castle is easily recognisable. A fine example of medieval military architecture, it first provided sanctuary to the Cathars, before becoming a royal estate. It was one of the "Five Sons of Carcassonne", the furthest French outpost facing the kingdom of Aragon. Today, abandoned, mighty and melancholic, it continues to defy time and the elements.