The fort, built on what in Roman times was a sanctuary dedicated to the god Apollo, has been the scene of numerous battles over the centuries.
Its current constitution is due to Gioacchino Murat, King of Naples, who used it in 1814 to block the way to the Austrians. The construction of the fort involved the leveling of the ancient remains that protruded the Roman terraces, used to set up the cannons facing downstream. At the highest level of the bastion you can still see, clearly visible, a small house used as a command post.
It belonged to the former Kingdom of Naples and was intended to defend the border between the latter and the State of the Church. The pass, as we know, was highly strategic since the Aurunci mountains with their gorges were difficult to cross, especially after fortification interventions.
The history of the place is quite suggestive: the first to use this position for military purposes were the Romans, who built this fortress above the Temple of Apollo to block Hannibal's way; Subsequently, as Gregory the Great tells us, a chapel dedicated to Saint Andrew (from whom the valley takes its name) was built on the fort to chase away the fearful devils who were said to infest the area.
The place, as I mentioned, has been the scene of numerous battles for control of the Kingdom of Naples since the 16th century and governed not only by Neapolitan, Papal, Spanish and Austrian armies, but also by famous brigands, such as the d'Arezzo of Itri and Papone, who in 1647 blocked the road to prevent the Spanish restoration. Then, in 1743, it was the Austricians, then masters of the Neapolitan area, who blocked the pass to prevent Charles of Bourbon from entering with the Spanish troops. In 1798 then came the turn of Michele Pezza (Fra' Diavolo, as he was known), another famous bandit who heroically defended access to the Kingdom against the French.