Castel Volturno is a "comune" (municipality) in the Province of Caserta in the Italian region Campania, located about northeast of Campania and about northwest of Caserta. its coastline is included in the Gulf of Gaeta.

The historic center stands on the left bank of the Volturno river, on the last loop that this forms before flowing into the Gulf of Gaeta in the Tyrrhenian Sea. The municipal territory covers an area of 72.23 km² and has 25 km of beach and 10 of pine forest. The southern part of the territory is an integral part of the Metropolitan Area of Naples, wedged between the Agro Aversano and the Giuglianese. The name derives from the presence on the banks of the Volturno river of a castle.

The castle of Castel Volturno was the main defensive structure of Castel Volturno, located on the last bend designed by the Volturno river before flowing into the Tyrrhenian Sea. To the original nucleus, probably from the 11th century, numerous structures have been added over the centuries, combined with often heavy renovations: currently, the castle is presented with the robe assumed during the restorations of the seventeenth and eighteenth centuries.

The tower of Patria, located at km. 43 of the Via Domiziana in Lago Patria, is among the examples of watchtowers and defense that has been best preserved, among the many that stood along the entire Domitian coast, despite the transformations suffered over the centuries.