Excavated around the first half of the second century AD, the Aqueduct consists of a tunnel as long as 50 kilometers, which from the mountain springs of Villamassargia and Domusnovas conveyed water to the city, which was unable to permanently drive out the centuries-old remora of supplying water with the pre-existing cisterns located in the hillsides, adjacent to the houses. In fact, the numerous underground reservoirs created by the Phoenicians and Carthaginians, once made communicating with the conduit excavated by the Romans, became extensive “settling chambers” and “limestone pools.” One of the most spectacular settling chambers equipped with channels for water distribution is located in the garden of the “Old People’s Rest Home” and is known as the “Victor Emmanuel II Cistern“. It is interesting to note how in the extra-urban section the spring water flow tunnel was dug into the ground, about 15 to 20 meters deep, and shows a lining obtained with impermeable stuccoes that hold together numerous fictile boards, the same ones that make the vault take on the classic “double-sloping” shape (or specus), commonly identified as “hump-backed.” Instead, in the urban section, thus under the streets and squares of Cagliari, we can ascertain that the same pipeline was dug completely into the rock, about 10 meters deep, and shows, almost two millennia later, the marks left by the stonemasons of the quarrymen.
In both the urban and suburban sections, the reach pipeline is equipped with numerous wells known as “puteums,” originally useful for facilitating the excavation of the cavity and later essential for water withdrawal and maintenance of the underground environment. Recently, prospecting by the G.C.C., which relied on the research of several scholars in the 1700s, has identified, during challenging explorations, several sections of underground pipeline that are restoring the original identity to the kilometer-long segment of Aqueduct that runs under the town.
