[2][3][4] The Latin-volscian[1] town stood in the Capo d'Anzio (modern Anzio), on a higher ground and somewhat away from the shore, though it extended down to it.

This was defended by a deep ditch, which can still be traced, and by walls, a portion of which, on the eastern side, constructed of rectangular blocks of tufa, was brought to light in 1897.

[3] The settlement of Roman Antium was certainly present in the area of the Capo d'Anzio (in particular, a presumed extensive town since the mid-republican age,[8] the imperial colony and the great harbour of Nero), but a parallel agricultural settlement, with the same name, was likely to be in the same position as modern Nettuno since the colony of 338 BC; so from 60 AD the colonia Antium of Nero in the Capo d'Anzio would coexisted with a supposed, more ancient, civitas Antium in Nettuno, which in the 4th century AD would have been the only real town:[3] [9] a thesis that has found some perplexities[10] or an opposition.

[14] In 468 BC Antium was captured by the Roman consul Titus Quinctius Capitolinus Barbatus following a war started by the Volsci, and the mentioned Latin colony was planted there the next year.

[16] In 338 BC the consul Gaius Menius Publius suddenly attacked and defeated the troops of Aricia, Lanuvium and Velitres as they were joining the Antiates next to the river Astura.

[2] During the civil war against Gaius Marius, Antium - breadbasket of Rome [22] - was allied with Sulla: in 87 BC it suffered a surprise attack and was devastated by the Marian troops, with many citizen deaths.

The Romans built magnificent seaside villas there and their remains are conspicuous all along the shore, both to the east and to the northwest of the town.

Many ancient masterpieces of sculpture have been found there: the Fanciulla d'Anzio, the Borghese Gladiator (in the Louvre) and the Apollo Belvedere (in the Vatican) were all discovered in the ruins of villas at Antium.

[5] Nettuno is usually attributed only a medieval origin,[4] but in the modern era it was considered a natural heir, a continuation of Antium;[27] [3] a view taken up by a contemporary orientation.