Attributed by tradition to Servius Tullius, sixth king of Rome, who probably built in the first half of the sixth century BC a ring of walls of which traces in cappellaccio stone still remain
Most of the wall still visible today, however, dates back to the first half of the fourth century BC. Livy writes that in 378 BC the censors of that year contracted the construction of a new wall to prevent further looting after the occupation of the Gauls in 390 BC. The wall was built of tufa stone from the quarries of Grotta Oscura accessible after the conquest of Veii of 396 BC
Restorations in the years 353, 212, and 87 BC
About 10 m (33 feet) high and over 4 meters (13 feet) thick in some spots
Total length was 11 km (6.8 miles), encompassing an area of 4.26 km² (1.6 square mile)
Although the area was not completely occupied, it was the largest town on the Italian peninsula
The LONGER SECTIONS STILL EXTANT ARE:
Two in Piazza dei Cinquecento, one 30 m (98 feet) long near the Diocletian Baths and one 94 m (308 feet) long by the front of Termini Station
Piazza Albania, 42 m (138 feet)
Piazza Manfredo Fanti, 23 m (75 feet)
THE SEVENTEEN GATES
Porta Catularia
It was located near the bottom of the steps of Capitoline Hill
Porta Fontinalis
Visible traces surrounded by flower beds in front of the Museum of the Risorgimento. It was the main gate to the north
Porta Sanqualis
Visible traces of the north side of the door in the center of Largo Magnanapoli
Porta Salutaris
Via the Dataria where the Temple of Salus used to be
Porta Quirinalis
Via Quattro Fontane, where the Temple of Quirinus used to be
Porta Collina
It was located at the northeast corner of the former Palace of the Ministry of Finance, at the intersection of Via XX Settembre and Via Goito. The remains found during construction of the Palace of the Ministry of Finance were demolished after being cataloged
From here the AGGER began, a fortified stretch of the wall more than 1,300 m (4,265 feet) long and 36 m (118 feet) wide, with a moat of 17 m (55 feet), which began at the Porta Collina and ended at Porta Esquilina. It was necessary in a vulnerable section of the wall where it was not possible to exploit the hillsides
Porta Viminalis
At the center of the agger, which corresponds to the current Piazza dei Cinquecento
Porta Esquiline
Still existing and known as the ARCH OF GALLIENUS. From here the Labicana and Tiburtina Ways exited as a single road, only to separate immediately after
Porta Querquetulana
Corresponding to the church of Ss. Quattro Coronati, or, according to a recent research, to the church of Sts. Marcellinus and Peter
Porta Celimontana
Still existing and known as the ARCH OF DOLABELLA
Porta Capena
Close to the short South East side of the Circus Maximus. From here the Appian Way and Latina Way exited as a single road, only to separate immediately after
Porta Naevia
Close to the church of S. Balbina on the small Aventine Hill
Porta Raudusculana
Viale Aventino near Piazza Albania
There is a section of the walls 42 m (138 feet) long with twelve layers of blocks of tufa and the arc of a room for artillery
A little further on another stretch 43 m (141 feet) long from which came the Vicus Piscinae Publicae corresponding to today's Viale Aventino
Porta Lavernalis
To the south of the Aventine Hill, at Via Marmorata
Porta Trigemina
Corresponding to S. Mary Cosmedin
Porta Flumentana
Corresponding to the Temple of Portunus
Porta Carmentalis
Corresponding to the sacred area of S. Omobono