Tunnels for Rome's third metro line now reach Piazza Venezia.

Excavations for Rome's Metro C tunnels from the Roman Forum to Piazza Venezia have been completed, the city's mayor Virginia Raggi announced.

"Another goal achieved in the construction of the third metro line of the capital, which will unite the suburbs to the heart of the city," Raggi posted on social media.

• Rome Metro C to reach Piazza Venezia

The mayor said the next step will be presenting the ministry of infrastructure with plans for the Piazza Venezia "station-museum," a reference to the planned display of excavated archaeological artefacts, similar to the S. Giovanni Metro C station.

History of Metro C

The Metro C line was originally meant to run from Pantano, in the eastern suburbs, across Rome's historic centre to a new station near the Vatican and even beyond to Piazzale Clodio. However, since the project began in 1990, it has been beset with difficulties. These have included funding overspends, lengthy delays and the abandonment of planned stations across the historic centre caused by the discovery of archaeological remains underground.

• Colosseum Metro C station to open in 2023

In 2014 Italy’s audit court accused the project’s consortium of cost overruns that were neither accounted for nor agreed, on the Pantano-Centocelle section. The court said that over €360 million of public funds were wasted between 2006 and 2010, and that the system was “designed to reward delays.”

In 2012 the court’s president Luigi Giampaolino said that Metro C seemed set to become “the most expensive and slowest public works project in Europe and the world.” Since construction began 29 years ago, the cost of the project has risen from €1.9 to more than €5 billion.

Metro C today

The driverless 19-km line currently comprises 22 stations and runs from Pantono in east Rome to S. Giovanni, where it connects with Metro A and the central Termini train station. With the opening of the Fori station, scheduled in 2023, Metro C will connect with Metro B.