Rome. For a long time, the Roman metro was the symbol of chronic impotence. With each pickaxe hitting an ancient column or an archaeological site, urban mobility projects were bogged down. This was the case for the section of line C which had to reach the Colosseum. A project worth nearly 800 million euros which has experienced numerous delays. Nearly twenty years after the promise of this extension and at the end of a project which lasted twelve years, it finally entered service on December 17. The two Colosseo-Fori Imperiali and Porta Metronia stations inaugurated constitute a small revolution. It is no longer the metro which is subject to the hazards of archaeological discoveries but the latter which become a driving force in the modernization of the deficient transport infrastructures of the Eternal City. But also one of its tourist attractions thanks to the concept of “archaeo-station”.
This segment of just three kilometers is much more than a simple extension of a metro line. It finally connects the southeastern outskirts of Rome to its historic city center. Its construction, which plunges up to 32 meters deep to overcome the water table and the densest archaeological strata, required the use of unprecedented engineering techniques. The challenge was met thanks to “ top-down archaeological”, a method of excavation in reverse stages which secures neighboring buildings while protecting the archaeologists’ time. At the heart of this system: 29,000 m³ of sifted earth and a network of 1,700 high-precision measuring instruments guaranteeing the integrity of the site. This strict protocol is now an international benchmark for construction sites in historic urban areas.
The largest preventive archeology project in Europe
In the new Colosseo-Fori Imperiali station, the multimedia device installed to inform travelers about the site is not limited to simple information screens. It was designed by the Colosseum Archaeological Park to accompany it in its journey through different eras. Video installations show how the district was transformed, from the Rome of the Etruscan kings to imperial Rome, up to the upheavals of the Alessandrino district (destroyed in the 1930s for the creation of Via dei Fori Imperiali). A ” oculus» (a circular window) located in the connecting corridor between lines B and C offers a real view of the Colosseum, located just a few meters away. Nearby screens complete this vision with digital reconstructions showing the amphitheater and its surroundings as they appeared during Antiquity.
One of the displays for the presentation of archaeological remains in the Colosseo-Fori Imperiali station.
© City of Rome
Under the foundations of the new station, the site has unearthed the vanished gardens of Villa Rivaldi as well as a succession of stratified complexes which until then only existed on paper. The major discovery lies in a network of twenty-eight wells, veritable archives of Roman water. If nine of them were simple boreholes in the compact silt of the Velia hill, nineteen others featured an apparatus of cut tuff slabs, today meticulously preserved. The sediments collected, dating from the 5th to the 1st centuries BC. BC, contained intact objects: ritual offerings left when the wells were sealed.
The construction site for the extension of line C, considered the largest preventive archeology project in Europe, not only served to uncover 600 objects integrated into the structure and offered for public admiration through glass walls; it made it possible to map entire neighborhoods that were previously unknown. This is the case of the imperial barracks from the time of Hadrian under Porta Metronia station. By entering, the traveler does not just validate a 1.50 euro ticket. He surveys a military domus from the 2nd century AD. The structures discovered during the work – a barracks and the luxurious “commander’s house” – were meticulously dismantled and then reassembled in situ within the station. A dedicated museum space, managed by the Ministry of Culture, will be inaugurated next spring.“We have transformed an archaeological constraint into an extraordinary knowledge opportunity for citizens”claims the mayor of Rome, Roberto Gualtieri.
The program for line C does not stop there: from the start of 2026, work on section T2 will begin. This future four-kilometre link will connect Piazza Venezia to the Prati district by 2035, marking the route of four new stations. The DNA of line C remains unchanged: transforming each construction site into an opportunity to enhance heritage. Future discoveries, inevitable in this historic sector, will be directly integrated into the architecture of the stations, confirming the success of the concept of archaeo-stations that are true underground museums.
