The second aqueduct of Rome, the Anio Vetus Aqueduct (or Aniene Vecchio), built in 269 BC, has the name that derives from the Aniene river while the suffix Vetus was attributed to it three centuries later when another aqueduct was built which took water from the same river: the Anio Novus. It follows the path of the Aniene river for over 63 km passing Tivoli to converge near the villages of Vicovaro and Mandela. The water was of poor quality – being taken directly from the river – and was therefore used for non-potable uses, such as irrigation and fountains in villas and gardens.

Conversely, from Tivoli, the aqueduct continued in the valleys of Gallicano, with a sinuous course to avoid the depths of the valleys (later monumental bridges such as the Ponte della Mola were built which shortened its route) and arrived in Rome along the via Prenestina near Porta Maggiore, from where it continued underground up to Piazza Vittorio, ending near the Porta Esquilina (or Arco di Gallienus).

Remains of the speco (conduit where the water flows) of the aqueduct discovered, reveal the construction features: with a rectangular section in tuff and covered with a thick layer of cocciopesto (for waterproofing).

The Aqua Tepula aqueduct was built in 125 BC. by the censors Cepione and Longinus, to capture the warm waters (it seems that the water had a natural temperature of around 17 degrees: hence Tepula) coming from the volcanic area of ​​the Alban Hills.

The fourth and last aqueduct of the Republican age, it was approximately 18 km long and, for the most part, overlapped the arches of the Marcio aqueduct (it can be seen in the Parco degli Acquedotti), from when it came to the surface, from the Villa dei Quintili to Porta Maggiore. From here it continued towards Termini station and Piazza della Repubblica, to supply the Baths of Diocletian. Its brick arches were taller and thinner than those made of tuff blocks of the Marcia. It had a very low water flow rate, the smallest of all aqueducts: only 198 l/s.

Commissioned by the consul Agrippa in 33 BC, the Julius Aqueduct captured the so-called Aqua Julia, in honor of Gaius Julius Caesar Octavian, the future emperor Augustus. 22.5 km long, of which 7 were on the surface (where it overlapped with the Aqua Tepula conduit), it had a flow rate of 566 liters per second and, considering its height, it seems it was used for domestic purposes in the highest districts of the city.

It collected water from the Squarciarelli springs near Grottaferrata, combining them with the nearby Tepula springs to improve their quality. In the Capannelle area the two conduits overlap with those of the Acqua Marcia to reach Porta Maggiore together. Here, taking advantage of the structure of the Aurelian walls, it reaches Porta Tiburtina and then continues underground towards the Viminale, the Termini station and ends near Via XX Settembre.

It captured the sources to the east on the Via Collatina near the locality of Salone but, near the town center and, to avoid crossing it, it circumnavigated it arriving at Campo Marzio from the North, through the Trevi Fountain to reach the Pantheon and the Baths of Agrippa. It had an entirely underground route up to the Piazza di Spagna, where it emerged on the surface (a stretch of it can be seen in Via del Nazareno and in the Palazzo della Rinascente in Via del Tritone) to feed some of the most magnificent fountains in Rome and in the world, between the Renaissance and the Baroque: Fountain of the Turtles (Giacomo Della Porta, 1584), the Barcaccia by Bernini (1627), the fountains of Piazza Navona (fountain of Neptune, the Moro and the 4 Rivers) and Piazza del Popolo, the Pantheon and the monumental Trevi Fountain (Nicola Salvi, 1761).

The name Virgo is to be attributed to the girl who, according to the legend, indicated the position of the springs that had been searched for so much in vain until then. But it is much more likely that this name refers to the purity and lightness of its waters which, due to the absence of limestone, did not block the duct, thus requiring low maintenance. This is what has allowed it to function to this day.

The Alsietino aqueduct was built by the emperor Augustus in 2 BC. (also called Aqua Augusta), took water from Lake Martignano (in the past called Atsetio or Alseatino) in the Viterbo area, north of the city.

About 33 km long (almost entirely underground), it brought non-potable water to Rome destined by the emperor Augustus to feed the Naumachia, his "aquatic arena", a large artificial basin where naval battles were held to entertain the people. The Colosseum itself was used as a naumachia, flooding the stage.

The largest and most impressive of the Roman stone aqueducts, monumental. Similar in features and technique to the Pont du Gard in Nimes which had just been completed at the time, it stands out in the Roman countryside for many miles to create an unmistakable and powerful landmark. Wanted by Caligula in 38 AD. to meet the growing demand for water of the expanding city, it was finished by Emperor Claudius (from whom it took its name) in 52 AD. together with the Anio Novus.

Almost 69 km long, it went up the Aniene Valley in search of the springs identified near Arsoli and Marano Equo with the names of Sorgenti Serene and the small lake of Santa Lucia. The water had a very high quality, inferior only to the Marcia. The flow rate is abundant: approximately 2150 litres per second.

The use of materials evokes the ancestor Marcio aqueduct, but here the use of peperino predominates (of higher quality than the more ancient aqueducts) and to a lesser extent inserts of red and yellow tuff. The stones are cyclopean (up to 3 meters long) and are dry-laid. A difference with the older structures is the presence of a more resistant and wider band at the base of the pylons which acts as an intermediary with the ground on which it rests.

A few years later, Nero built a branch of it to supply the nymphaeum and the lake of his Domus Aurea. Later, Domitian extended it to the Palatine (where part of it is still visible) and to the imperial palaces present there.

Like the Claudian aqueduct, the Anio Novus (or Aniene Nuovo) was also commissioned by Caligula and finished building in 52 AD. by Emperor Claudius. Defined as Novus to distinguish itself from its ancestor Anio Vetus, it winds east along the Aniene Valley and shares for the most part the route of the Marcio and Claudio aqueducts, passing them to continue up to the gates of Subiaco. 87 km long, it is second in length only to the Marcio.

The part that rises above the surface on arches overlaps for a long stretch with the Claudio Aqueduct, as can be seen in the Aqueduct Park. The two aqueducts are distinguished by their materials and technique: the tuff block arches of the Claudio contrast with the speco of the Anio Novus made instead of brick and reticulate work.

It is the aqueduct with the highest water flow rate among the eleven ancient ones, almost 2,300 l/s.

Wanted by Emperor Trajan in 109 AD. to supply Trastevere, it reached as far as Lake Bracciano taking water from the springs of the Sabatini mountains. Starting from the north, it follows a long route that winds between Via Cassia, Clodia and, taking the Via Aurelia Antica, the Trajan aqueduct passes by Villa Pamphili passing under the Arch of Paul V and reaches the Janiculum.

Long 57 km, it had a flow rate of more than 1,300 litres/second. Repeatedly renovated and modified over time, it was finally rebuilt in the 1600s on the ancient pipelines and today is the modern Aqua Paola aqueduct, inaugurated in 1618 by Pope Paul V, which flows into the well-known Fontanone del Gianicolo, completed years later in 1690.

The last of the Roman aqueducts, the Alexandrian Aqueduct was built in 226 AD. at the behest of Emperor Alexander Severus. Its route (22 km) winds between the consular streets via Prenestina and Casilina until it reaches the springs in the locality of Pantano Borghese, on the outskirts of the capital, the so-called. Aqua Alexandrina. The Aqueduct stands out imposingly with its arches in the eastern quadrant of the city, skirting the neighborhood of Centocelle and cutting across Palmiro Togliatti, becoming the star of the Tor Tre Teste park overlooking the "white sails" of the church – Dives in Misericordia – designed by star architect Richard Meyer.

Product of the technical achievements of 5 centuries of technological progress since the first aqueduct, it has a structure in cement work and external facing in brick. The aqueduct, almost entirely above ground on "slender" and high arches (over 20 metres) is excellently preserved and visible in a good part of the city. About 22km long, it had a low flow rate of around 255 litres per second. The springs, located on the Via Prenestina near Colonna, were then taken up by the Felice Aqueduct many centuries later.

Its waters were necessary to supply the Nero Baths, which the emperor himself renovated, renaming them the Alexandrine Baths.

After the fall of the Roman Empire, centuries of political and economic instability followed in the capital. Wars, looting and vandalism soon led to the ruin of the city and its most important works. Even the aqueducts were devastated: in the Middle Ages many of them were no longer able to function. We must arrive at the Renaissance, after a thousand years of abandonment, for the city to flourish again: art, architecture, economy and population began a new, flourishing period. Even the aqueducts reduced to rubble were repaired and returned to function.

Alongside the 11 aqueducts from the Roman era, a twelfth was added in the Renaissance: the Felice Aqueduct.  The aqueduct is called Felice in honor of its creator, Pope Sixtus V, born Felice Peretti, who strongly desired it. Defined as a "tough pope" in a verse by the Roman poet Gioacchino Belli, in just 5 years of pontificate, he overturned and renewed the face of the Eternal City: he built aqueducts and fountains, palaces and streets, and had obelisks erected in the main squares.

The Felice aqueduct, like some of its predecessors, follows the existing aqueducts for long stretches.  Apart from the Claudio Aqueduct, with which it shares a good part of the route, it is the Marcio aqueduct which is "given" entirely to him and was also demolished to make room for the new construction and its stones reused.

Between Porta Maggiore and Porta Tiburtina it follows the structure of the Acqua Marcia and runs parallel to the Aurelian Walls (3rd century AD). Near Porta Furba, at the end of Via del Mandrione, there is the Acqua Felice exhibition commissioned by Sixtus V. The Mandrione fountain was restored in 1733 on the initiative of Pope Clement XII (as the inscription reports).