The castle of the Waldensians of Guardia Piemontese rises in the heart of the old town. Dating back to the fifteenth century, it still has a well-preserved watchtower, which was built to sight the arrival of Saracens and pirates. The structure of about 20 m. in diameter, with walls almost 2 m. thick, has an octagonal vault and was perhaps divided into two floors. The town owes part of its name to the watchtower.
