Within the boundaries of Sant Just Desvern, at the border with Sant Feliu de Llobregat and alongside the Iberian settlement, stands a medieval fortification on Penya del Moro hill, formerly known as Puig Castellar. According to Pagès (1992) the remains of the circular base correspond to the castrum mentioned in a document in 1050, like the one that perched above the town and parish of Sant Just Desvern. The tower of the fortification was built on top of the ruins of an Iberian tower. Even though it was initially believed that there was only a tower here, excavations revealed a larger structure with three additional spaces surrounded by defensive walls, as a result of which the site was reclassified as a castle.