Construction was underway this week on the Metro C subway main hub in Piazza Venezia in central Rome.
Rome CNN  — 

Rome, as it’s often said, wasn’t built in a day. And nowhere is that more evident than its state-of-the-art Metro Line C, an ambitious project meant to help relieve the Italian capital’s renowned traffic hellscape and celebrate its rich archeological history with a unique-in-the-world underground museum.

The €700 million line ($757.7 million) was originally envisioned for the Catholic Jubilee of 2000 as a vital link between Rome’s San Giovanni Cathedral and Vatican City’s St. Peter’s Basilica, making it easier for visiting pilgrims to collect indulgences by walking through the churches’ holy doors. Rome’s major basilicas open their holy doors only during Jubilee years, allowing Catholics from all over the world to make pilgrimages to the city to walk through them, symbolizing an openness to receive mercy and reconciliation.

Pope Francis opens the "Holy Doors" at St. Peter's Basilica to mark the start of the Jubilee Year of Mercy.

But the 2000 dream never happened, thanks to a series of problems ranging from a corruption scandal in the city government and the sheer number of archeological objects – 40,000 in all, from petrified peach pits to pottery and vases and even the walls and mosaics of Emperor Hadrian’s 2,000-year-old military barracks – found with each shovel full of dirt during the initial preparations.

Now the hope is to have the line’s showcase Piazza Venezia stop, featuring an eight-story underground museum, ready in 10 years, according to engineer Andrea Sciotti, who is in charge of the metro museum complex. This will allow them to open around the Jubilee of 2033, which will mark 2,000 years since the death of Jesus Christ.


“It’s true, 10 years seems like a long time, but we aren’t just dealing with the engineering issues,” Sciotti told CNN inside the construction site. “This station will be judged as the most beautiful in the world … we don’t have to rely on museum items being brought in, the museum station is in its original context in ancient Rome.”

Emperor Hadrian's barracks were discovered in 2016.

Displayed where they were found

During the initial phases of work carried out in the last five years, Sciotti said all of the artifacts were removed from the site for restoration. Each will be placed exactly where it was found inside the metro museum, which is being dug some 85 meters (280 feet) deep, encompassing eight stories below the modern city of Rome.

Over the millennia the modern city has been built over covered ruins. Only around 10% of ancient Rome has been excavated, with the rest still buried some nine meters (30 feet) below the current city, according to Rome’s tourist bureau. The city dates back to the stone age and construction work is notoriously hampered by the discovery of ruins that are too plentiful to even excavate and are often reburied to preserve them. Even simple infrastructure work, like sewage repairs, have to be attended by archeologists who have the power to stop the work if something is found.

There will be 27 escalators, six elevators and 66,000 square meters of archeological exhibit space. Ancient walls found during excavations will be placed “in situ” in the modern station and the ancient Via Flaminia that ran through the ancient city to the nearby Roman Forum and Colosseum.

The station’s three main entrances will connect the three museums around the square: the Vittoriano, the Palazzo Venezia and the outdoor ruins of the Roman Forum anchored by the Colosseum at the far end, which has its own metro station that will also feature museum and exhibit space.

Several of the archeological sites will have access points from inside the metro museum, meaning commuters and tourists alike can exit the station by rambling through historically significant ruins like Hadrian’s Auditorium, which was discovered when the initial archeological investigation into the project started and was meant to be the location of the station entrance. Since then, they moved the site and excavated the ruins, which are currently only visible looking down from street level.

Artifacts from the excavation on display in 2018 at San Giovanni station.

‘Top down’ excavation system

To secure the site as they dig, engineers are using a “top down” excavation system, which has never been used in Italy but was an integral part of the Jubilee line in London. Cross walls and diaphragms are being buried deep into the soil to form the perimeter of the underground complex, with the dirt taken out recycled and enhanced to be used in the building materials, Sciotti said.

The train tunnels themselves are not the issue since they will be more than 100 feet below ground.

“It’s getting to that level that we have to wade through the artifacts that causes the delays,” he said, noting that they are passing through Medieval and Renaissance eras.

The Venezia station museum stop is not the only treasure on the new line. In 2016, archeologists working on the site of the Porta Metronia (previously known as the Ambra Aradam) station found a 39-room complex that spanned more than 9,700 square feet that has been incorporated into the underground station, which will open by the end of 2024. In 2025, the new Colosseo-Fori station, complete with a four-level underground museum to showcase artifacts including 25 archaic wells unearthed when it was built, will also open after activation tests, meant to begin in October, are completed.

The entire 26-kilometer C-line will be Italy’s first fully automated driver-less subway system and will reduce road traffic by 400,000 vehicles a day, meaning CO2 emissions will be reduced by some 310,000 tonnes a year, according to the WeBuild group, which is the main contractor for the project.

The original plans from the 2000 Jubilee have been modified to eliminate several stations in the historical center that would have simply been too difficult to excavate.