The castle of Villasor, in the province of Cagliari, is one of the rare examples, in Sardinia, of a fortified noble house. For its architectural features, it is easily referable to the typology of the masia, a sort of fortified baronial farm, evolution, of Spanish origin, of the villa of Roman times. Built at the beginning of the fifteenth century, the manor house, however, has schemes and construction modules closely linked to the previous century, for formal layout and technical-structural conception. Over the centuries it has undergone profound transformations linked to changing functional requirements, gradually losing its defensive vocation to residential and agricultural ones.