Prima Porta is the 58th zona of Rome, identified by the initials Z. LVIII. The name Prima Porta (First Door) came from an arch of the aqueduct that brought water to the Villa of Livia, which formed over Via Flaminia a sort of gateway which travellers saw as the first indication of having reached Rome (Piperno).

The location was strategically important due to the iron-rich cliffs of red tuff that approach the river at this point, the confluence of several roads, and its function as the north entryway to Rome.

Prima Porta was one of the scenes of Constantine's victory over the army of Maxentius in 312 which ended with the Battle of the Milvian Bridge. The battle is shown in the frieze of the Arch of Constantine in Rome. A triumphal arch was also erected here.

Nearby, the villa of Livia Drusilla called Ad Gallinas Albas was probably part of Livia's dowry brought to the Julio-Claudian dynasty. It was named and famous for its breed of white chickens and for its laurel grove (Pliny's Natural History 15.136f), which were given auspiciously omened origins by Suetonius. The villa's site was rediscovered and explored as early as 1596, but it was not recognized as that of Livia until the nineteenth century.

In 1863–1834, a marble krater carved in refined low relief was discovered at the site and in 1867 one of the most famous marble statue of Augustus, the Augustus of Prima Porta, which is now in the Vatican (Braccio Nuovo), was discovered here. The magisterial Augustus is a marble copy of a bronze statue that celebrated the return in 20 BC of the military standards captured by the Parthians in 53 BC after the defeat of Crassus at Carrhae: a rich iconography plays out in the low reliefs that decorate his cuirass.

The villa occupied the height dominating the view down the Tiber Valley to Rome; some of the walling that retained its terraces may still be seen (Piperno). Except for works of terracing—the gardens are currently being excavated—, all that can be seen today are three vaulted subterranean rooms, from the largest of which the fine fresco decor of an illusionistic garden view, where all the plants and trees flower and fruit at once, was removed to Rome; it has recently been reinstalled in the Palazzo Massimo, following cleaning and restoration. The vault above the fresco was covered with stucco reliefs of which only a few remains survive.

The villa was built and modified in four stages, the earliest of Republican date, the latest of the time of Constantine the Great. In the nineteenth century the villa belonged to the convent of Santa Maria in Via Lata; it may never have passed into private hands.

A new series of more meticulous modern excavations was initiated in 1970.