The Roman Astura was a landing place at the mouth of the Astura river and seat of Roman villas as early as the 1st century BC. One of these was by Cicero, and Astura was the scene of the last phases of his useless flight from Marcus Antonio. On the site, between the end of the Republic and the beginning of the Imperial age, a villa was built partly on the mainland and partly on an artificial island, equipped with a large fish pond, the remains of which are still partly visible. Starting from the Roman age, Astura represented the extension and the eastern border of the colony of Antium (Anzio) and for its amenities it was a place much loved by the Roman nobles who chose it to build their villae d’otium.
Received around 1140 to Tolomeo dei Conti di Tuscolo for having usurped it from the monastery of Sant'Alessio all'Aventino, in 1193 the site came into the possession of the Frangipane, who to protect themselves from the Saracens built a maritime fortress with a pentagonal tower. surrounded by water and connected to the mainland by a brick arched bridge.
In 1268 Corradino di Svevia, defeated near Tagliacozzo, took refuge in Astura in the tower of the same name, but Giovanni Frangipane, lord of this land, handed him over to Charles of Anjou, king of Naples, so that he was beheaded in Campo Moricino, the current market square in Naples.
In 1426, after having been a fief of the Caetani and the Orsini, the fortress passed under the Colonna family who restructured it, giving it its current appearance, and sold it in 1594 to Clement VIII Aldobrandini. From these, when the Aldobrandini family died out, it passed to the Borghese family, from whom it was sold to the municipality of Nettuno in the seventies of the twentieth century.