Prima Porta is a suburb of Rome located 12 kilometres north of its center along the Via Flaminia and just a kilometre outside of the Grande Raccordo Anulare highway. It is located on the right bank of the Tiber where the Via Tiberina leads away from the Via Flaminia and another road led off along the Cremera to Veii (Latitude: 42.000992° - Longitude: 12.493380° ). 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 entry point to Rome. Parrocchia Santi Urbano e Lorenzo a Prima Porta, is the name of the Catholic Parish. It is looked after, the location of and serves as a House of formation for the Pauline Fathers.
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).
One of the most famous statues of the Divine Augustus was found in the general area of Prima Porta in 1863.
In 1965, heavy rains made two near Tiber tributaries, which had no protective banks, to flood the area, generating infrastructural and economic damage. Water level was two meters high at some points.
Prima Porta houses, along the Via Flaminia, Rome's biggest cemetery, Cimitero Flaminio, also known as Cimitero di Prima Porta.
The population of the XV Municipio (formerly the XX Municipio), the administrative unit that includes Prima Porta, was 146,000 as of the census of June 7, 2001.
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 1863/4 a marble krater carved in refined low relief was discovered at the site and 1867 the heroic marble statue of Augustus, the Augustus of Prima Porta, which is now in the Vatican (Braccio Nuovo). 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 after the defeat of Crassus at Carrhae: a rich iconography plays out in the low reliefs that decorate his cuirass.