An excerpt from Wanted in Rome:

"This time it’s for real,” began a report in daily newspaper Leggo on 6 March. Except, once again, it wasn’t quite. Since December 2006 Rome’s media has been running premature reports heralding the opening of the first building sites for Rome’s new metro C line – a high-tech, world-class system that should eventually connect Grottarossa in the northern suburbs to Pantano in the south-eastern suburbs, as well as providing much-needed coverage through the “hole” in the city centre that is bypassed almost entirely by the existing metro A and B lines.
But at the beginning of April, Roma Metropolitane (the city-owned company in charge of the expansion and modernisation of the capital’s metro system) finally confirmed the opening of the first building site at Piazza Roberto Malatesta, with two more set to open by the end of the month. All three are on the seven-kilometre stretch between S. Giovanni and Alessandrino in eastern Rome, which forms the initial stage of the line’s construction and will link eight new stations to the current S. Giovanni metro A stop. Even though work is finally underway, it will be at least eight years before Rome residents see metro C completed.
The S. Giovanni-Alessandrino stretch (roughly between Via Casilina and Via Prenestina to service the new residential and office developments around Centocelle) is due to open to the public in February-March 2011. In October 2006, Rome’s mayor Walter Veltroni announced that the opening of the Alessandrino-Pantano stretch (coasting Via Casilina and taking in the university area of Tor Vergata, the suburb of Tor Bella Monaca and beyond), which was due in autumn 2013, would be brought forward to spring 2011 as well, with work set to begin in January 2008. The Venezia-S. Giovanni and Clodio/Mazzini-Venezia stretches, which run through the historic centre of Rome, are set to open in autumn 2013 and summer 2015 respectively. Then in March this year the city council announced an extension to the north: from Clodio/Mazzini in Prati – the originally planned terminus of metro C – to Grottarossa on Via Flaminia, also due to open in 2015.
It is an ambitious timetable. In a city standing on a huge underground museum, complications and delays are inevitable, particularly along the Clodio/Mazzini-S. Giovanni stretch. In 2006, some 26 archaeological sites popped up over the city as teams from Rome’s Soprintendenza Archeologica, headed by superintendent Angelo Bottini, tested the ground for important ancient structures.
Although the tunnels for metro C will be built around 30 m below street level – and way below the strata carrying evidence of human habitation – the problems arise in building escalators, lifts and stairs to enter and exit the stations and ventilation vents from the tunnels. These will need to be carved through layers of history. Bottini’s teams will have to sift through a total of 60,000 cubic metres of soil before engineers can move in. A further 500,000 cubic metres will have to be checked during the construction phase. The finds the teams make have one of three fates depending on their importance: they are removed, destroyed or preserved in place. But every find slows the process and major discoveries will mean engineers will have to reroute exits and stations, dodging the ancient relics.
The city’s existing metro B line (built in 1955) and A line (inaugurated in 1980) both took around 15-20 years to build, partly due to ancient remains blocking the way. The metro A stop in Piazza della Repubblica was especially complicated, as workers hit parts of the huge third-century AD Baths of Diocletian complex and had to rethink the station around them.
“It’s like a slalom course,” Bottini was quoted as saying in the Wall Street Journal in January, describing the planning of the C line.
But the great irony of blasting holes through the centre for a new metro is the opportunity to dig in areas that would otherwise be off limits. In January this year, Fedora Filippi, the archaeologist in charge of the metro C site at the church of S. Andrea della Valle in Rome’s historic centre, hit a wall four metres below street level. Four metres deep, the wall was made from a cement of travertine marble and mortar and was clearly a relic of imperial Rome. The find was situated in the heart of the city’s ancient Campus Martius, between the Baths of Agrippa to the east and the Stadium of Domitian to the west.
From descriptions of the area by first-century BC Latin and Greek writers including Ovid and Strabo, Filippi knew that the wall could well be part of the foundations of the Stagnum of Agrippa, an enormous artificial pool in the gardens of the Baths of Agrippa complex built around 25 BC. A general who was also appointed aedile of Rome (responsible for the maintenance of public buildings) in the reign of the emperor Augustus, Agrippa also built an early rectangular version of the Pantheon around the same time.
The stagnum is perhaps most famous for appearing in a story about a dinner cruise from the life of the emperor Nero (37-68 AD) in the Annals of Tacitus, writing at the start of the second century AD. Nero and his guests were towed on a raft on the stagnum, which had been filled with “birds and beasts procured from remote countries and sea monsters from the ocean” and was bordered by brothels of noblewomen on one bank and naked gesturing prostitutes on the other.
But rather than continue their investigations into whether the wall discovered really is part of the stagnum, or whether it perhaps forms the foundations of a temple built later over the same site, Filippi and her team had to cover up their discovery and move on to other excavations. The riddle of the stagnum must temporarily be put aside until the rest of the work is done.
Among other discoveries made so far during the excavations, teams digging at Porta Asinaria, Via Amba Aradam, Viale Ipponio and Via Sannio in November 2006 discovered that the Aurelian Walls, built by the emperor Aurelius in 271 AD to defend the city from barbarian invasions, were twice as high as had been previously thought – around 20 m, rather than the 7-10 m that can be seen today.
Other treasures almost certainly still lie in wait since at some sites archaeologists have yet to hit the Roman strata of soil. At Piazza Venezia the team had only arrived at the late mediaeval stratum by mid April and had already discovered the remains of a 15th-century glass factory significant enough to require a change of plans: the Piazza Venezia station will likely be shifted from the centre of the square to another location – possibly to the entrance of Via dei Fori Imperiali.
“The station at Piazza Venezia must be built,” Bottini told daily newspaper La Repubblica following the find. “But we need to work out where the clash between the metro line and antiquity will cause the least damage.”
The first tunnel boring machines, or talpe (moles), are due to start work on the S. Giovanni-Alessandrino stretch of metro C in March 2008. Perhaps it is only when they are steadily forging galleries many metres below our feet that it will be safe to say the new line is really under way.