Lapped to the west by the Tiber, the Municipio is also crossed by its tributary the Aniene, the second river of the capital, which runs alongside the areas of Monte Sacro, Sacco Pastore and Conca d'Oro.

The latter are more recent findings, dating back to about 100,000 years ago,[5][6] were discovered between 1929 and 1935: a Neanderthalian skull was found for the first time in Italy near Sacco Pastore by the paleoanthropologists Alberto Carlo Blanc and Henri Breuil.

In fact, between the 2nd century BC and the 1st century AD the area around Monte Sacro had surely to be dotted with villae having productive functions: in addition to the many archaeological finds of fragments of amphorae and large food containers, artifacts dating back to the imperial age were found, which attest the presence of villae where fruit trees, wheat, flowers, vegetables, olive trees and vines were grown, in today's areas of Monte Sacro, Fidene, Colle Salario, Vigne Nuove, Bufalotta, Serpentara, Tor San Giovanni, Prati Fiscali, Settebagni, Castel Giubileo and Magliana.

[19][20] The archaeological excavations also brought to light a funeral urn with an inscription dedicated to Claudia Eglogae:[21] this woman was the nurse of Nero and, together with Acte, collected the body of the Emperor and transported it to the tomb of the Domitii.

[25] Furthermore, the remains of a villa called Redicicoli del bene were also found near Settebagni: This site, damaged during the construction of a complex of townhouses, was probably inhabited until the 5th century AD.

The excavations were carried out by the Soprintendenza Archeologica di Roma in 1984 and brought to light the remains of a rustic building together with two tanks used for the production of oil and wine, which are still visible today.

[29] In the Middle Ages there was a great depopulation of the area which today corresponds to the Municipio IV, but the urban centers of Capobianco, Fidenae and Monte Sacro were not involved.

An opposite situation occurred in Colle Salario (and therefore probably also in the contiguous areas of Castel Giubileo) and along the Via Nomentana, near the place of the martyrdom of St. Alexander, where there was a great demographic increase.

The expansion of the inhabited territory mainly affected the areas close to the religious centers of St. Michael the Archangel, Castel Giubileo and St. Alexander, as well as the surroundings of other churches.

For many scholars, the phenomenon can be explained by the fact that, after the increasingly frequent barbarian invasions, the churches became a place of aggregation for the population, especially if working in agricultural activities.

An example is a Roman sepulcher of the 1st century BC located near Ponte Salario: in the Middle Ages it was used as a watchtower for defensive and surveillance purposes and in 537 the so-called Torre del Caricatore was built on it.

The Governor of Rome, Filippo Cremonesi, and the President of the Istituto Case Popolari, Alberto Calza Bini, promoted a plan concerning the construction of a Garden city[34] in the area of Monte Sacro: it should have been the largest in Italy and in the world.

The construction, based on a project by Gustavo Giovannoni, was entrusted to an association called Consorzio Città Giardino Aniene, formed by the Istituto Case Popolari and the Unione Edilizia Nazionale.

According to the project, some essential services for the development of the Garden city would have arisen near Ponte Tazio: the park, the post office, the cinema-theater, the shops and the church.

But, after World War II, to stop the rampant growth of unemployment, the State decided to intervene with plans that would allow the development of housing activities in the area.

Even the ancient Fidenae was affected by the post-war building phenomenon, in spite of an ordinance dating back to 1962 which provided for an exclusively agricultural use: therefore a new urban zone called Fidene was created between the 1960s and the 1970s.

Neighboring areas, such as Castel Giubileo, were built in the same years, while, after 1962, the growth of the quarter Vigne Nuove received new impetus with the construction of public housing promoted by the Istituto Autonomo Case Popolari.

After 1970, what was then called "IV Circoscrizione" experienced a great building growth not only along Via delle Vigne Nuove, but also in other areas such as Conca d'Oro, Val Melaina, Nuovo Salario and Serpentara.

The phenomenon of urbanization did not stop even in the quarter Talenti: in the years between 1995 and 1998 the building plans involved the large green extensions between Via Gaspara Stampa, Via Nomentana and Via di Casal Boccone.

This quarter, partly still under construction and enclosed between Colle Salario and Vigne Nuove, is growing around a large green area: Parco delle Sabine.

It should be noted, in conclusion, that in recent years a greater ecological awareness has slowed down urban development and allowed to preserve numerous green areas in the Municipio.