On a promontory stands the medieval castle of the d’Aquino family, recently restored, with at its centre the mighty three-storey quadrilateral keep, once a Norman tower; the remains of the perimeter walls with quadrangular, cylindrical and semicircular turrets (13th-15th century ruins) outline the plan of the castle.
Of great interest is the Chapel, built (1334) on the ruins of the Chamber where St. Thomas Aquinas was born.
In the courtyard of the castle there was also the magella of the well, made of stone with hexagonal crowning, with sculpted coats of arms (14th century) and which has now been placed near the former cathedral as a baptismal font.
