In addition to the Roman Colosseum, one of the New 7 Wonders of the World, there are from imperial palaces to churches with excavations, several routes allow you to explore ancient vestiges under streets, squares and parks of the Italian capital.
Under the streets of Rome, several meters from the traffic, churches and squares, a network of underground sites opens a way to read the hidden history of the Italian capital. Imperial palaces, housing complexes, temples, cisterns and ruins of old streets form an archaeological map that remains outside the most crowded routes of the city. According to National Geographic, several of those spaces can be visited today and offer a different perspective on almost three thousand years of urban occupation.
The overlapping of constructions, demolitions and new works turned Rome into a city built on its own remains. According to the National Geographic report, that process left ancient structures buried at depths that in some cases exceed 9 meters.
This underground landscape is not limited to a single monument: it extends under the historic center and appears both under parks and public buildings and under Christian temples and squares of everyday use.
A superimposed city below street level
The layered structure summarizes the material history of Rome. Adriano Morabito, speleologist and president of Roma Sotterranea, told National Geographic that the Italian capital “is like a large lasagna,” made up of strata from different eras that grew irregularly. There are several Romes, one on top of the other, each conditioned by the previous one.
This explains the delays in infrastructure works. National Geographic indicated that each major intervention can expose archaeological remains. One case is metro line C, whose completion is projected for 2034 due to findings during its construction.
The underground network is difficult to measure. Morabito estimated that between 5% and 10% is known; many parts are still hidden under modern buildings, so the subsoil of Rome is an incomplete archive, enough to show the continuity of urban life since Antiquity.
In Piazza Navona, the oval shape preserves the footprint of the Domitian stadium, built in 86 A.D., almost 4.5 meters underground and visitable from a nearby access. UNESCO identifies it as part of Rome’s historical heritage and allows us to see how the modern city reproduced traces of ancient urbanism.
From the palace of Nero to the City of Water
Among the best known underground complexes is the Domus Aurea, a residence attributed to Nero after the fire of Rome in 64 AD. The site covers the Colosseum Valley and the Palatine and Esquiline hills. National Geographic reported that the palace occupied at least 40 hectares, with gardens, vineyards, artificial lake, banquet halls and hundreds of rooms decorated with gold, marble, ivory and precious stones.
Although older and closer to the Colosseum, the Domus Aurea receives less attention. Part was buried more than 9 meters deep. Only a fraction was excavated and opened to the public; the rest are probably still under the city.
Visits depart from Colle Oppio Park, in front of the Colosseum. Visitors pass through galleries, mosaic floors, rooms with high ceilings and remains of monumental fountains. There is a virtual reality experience that reconstructs the palace and shows the artificial lake where the Flavian amphitheater was later built.
The Vicus Caprarius, the City of Water, is near the Trevi Fountain. About 9 meters below the street, it preserves remains of an insula converted into a private domus and a cistern connected to the Aqua Virgo, an aqueduct from 19 BC that still supplies several sources.
Lorenzo Dell’Aquila, director of the Vicus Caprarius, told National Geographic that the ensemble shows the development of Roman hydraulic engineering. “It perfectly demonstrates the level reached by hydraulic engineering in Roman times,” he said. The complex was hidden under the old Trevi Cinema and was discovered after renovation works at the beginning of this century.
Water is key in the underground history of Rome. The city is crossed by the Tiber River and sectors such as the old valley of the Roman Forum had a direct link with swampy areas and underground currents. Under the temple of Emperor Claudius, on the hill of Celio, there is a medieval quarry, remains of a monastery and reservoirs of water of great purity that, according to Morabito, are still part of specialized speleological tours.
Churches, houses and traces of everyday life
Rome’s hidden heritage includes more than palaces or hydraulic infrastructure. Under several churches in the historic center there are spaces that show the domestic, commercial and religious life of different eras. Morabito told National Geographic that many can be visited with low entrance and without reservation, guided by scavi or sotteranei signs.
The Basilica of San Clemente, from the 12th century, near the Colosseum, with two archaeological levels stands out: the first is the original medieval church, from the fourth century, and further down there are Roman remains from the 1st century AD, such as a mitreum, a public building and an alley with the old urban layout.
There is also the Basilica of Santa Cecilia in Trastevere, from the 9th century, on the supposed house of Cecilia. About 2 meters below the current temple there are remains of that house, black and white mosaics and a marble crypt with Byzantine decorations.
The Roman houses on Celio Hill, under the Basilica of Saints John and Paul, are part of the circuit. The complex covers four centuries and contains workshops, deposits and residences, including those associated by Christian tradition to John and Paul. The site allows us to understand the ancient city from everyday life more than from the great monuments.
“History is just a gigantic puzzle of micro-stories,” said Dell’Aquila. That definition summarizes the value of a network that not only exposes the imperial past of Rome, but also the houses, streets, shops and services that sustained urban life for centuries.