The village is right in the centre of the town and represents what remains of the medieval period and the old Antium. It is the ancient Castle of Nettuno, consisting of compact walls, defended by imposing cylindrical towers, which surround the village, high on a high sea cliff. The towers date from the late fourteenth century, when Nettuno was under the rule of the Orsini. In the heart of the village stands the Baronial Palace, symbol of feudal power as the place of residence of the Colonna family that controlled Nettuno from 1426 until 1594. In this period of Marcantonio Colonna at the sixteenth-century palace, architectural style of that period characterizes it.