It’s little wonder we call Rome the Eternal City. A rich architectural legacy spanning more than two millennia bridges today’s metropolis with the city of the Caesars and the Rome of the Popes. In the centre, you can barely turn a corner without stumbling upon something special — a triumphal arch. An ancient temple. Even an Egyptian obelisk.
So much has survived from Rome’s heyday that we think we know the ancient city well. Scratch beneath the surface, however, and you find that much of Rome remains hidden. This isn’t to undervalue Rome’s main ancient attractions. The Roman Forum was the ancient city’s hub, a melting pot of international trade, social ostentation, and political conspiracy.
The Colosseum (or the Flavian Amphitheatre as it was then known) was Rome’s main arena: a sporting arena-cum-bloodbath where the imperial elite put on shows to placate the city’s plebeian masses—part of their diet of “bread and circuses,” as Pliny the Younger once wrote. But when the Roman Empire fell, the city of the Caesars fell with it — its pagan monuments destroyed, converted into churches, or, more often than not, simply built over.
We have uncovered but a fraction of the ancient city that underlies today’s capital. And while some monuments, like the Pantheon, have survived haphazardly (in this case because of its eleventh-hour conversion into a Byzantine church), many of the Eternal City’s monuments remain obscured, consigned to the subterranean city known as Hidden Rome.
This article introduces you to some of the highlights of Hidden Rome, some of which rival the Colosseum in terms of scale and the Pantheon in terms of ingenuity. And we start in a place better known for its Christian rather than pagan past: the Vatican.
Caligula’s Circus
Visitors to the Vatican are rightly awestruck by its architecture. Michelangelo’s dome looms large above Saint Peter’s Basilica, fronted by the thicketed columns of Bernini’s square. It’s no surprise that these imposing medieval structures dominate attention. This is after all the beating heart of Christianity. But the square’s keener-eyed visitors might rightly stop to ask themselves what a thirteenth-century BC Egyptian obelisk is doing in its centre.
It’s a good question. And like most about the Eternal City, it comes with a colourful answer.
The Vatican Obelisk was brought to Rome from Egypt in 37 CE by the mad, bad, and dangerous-to-know emperor Caligula, who had a ship built especially for the task. Caligula initially erected the obelisk in his private gardens before moving it to the spina (central barrier) of his circus (completed by Nero), which now partly underlies the western wing of Saint Peter’s Basilica.
One of the most intriguing highlights of hidden Rome.
Here the obelisk remained until 1585. Then Pope Sixtus V set about the 13-month project of reassembling and moving it to its present location. Because this red granite obelisk weighs 330 tonnes, this was no easy task. And so Sixtus entrusted it to the expertise of the famed architect, Domenico Fontana.
For the task Fontana acquired 40,000 pounds of hemp rope, 72 horses, and 900 men. But even this proved insufficient. At one point, while the obelisk was being winched up, the hemp ropes holding it in place started to fray. The gathered crowd, threatened with execution should anyone utter a sound, stood silent, shocked, until an experienced Genovese sailor cried out, “Water on the ropes!”
Fontana duly obliged, ordering his men to douse the ropes and thereby strengthening them. Thanks to the sailor’s intervention, the obelisk was winched up and saved from obliteration. As for the sailor, instead of being put to death for speaking out, he was handsomely rewarded. Sixtus declared that from henceforth the Vatican would buy all its Palm Sunday fronds from the sailor’s hometown of Bordighera. It’s a promise the papacy keeps to this day.
Domitian’s Stadium
Wander upon Piazza Navona and you’ll immediately be struck by the strangeness of its shape (not least because, unlike most piazzas, it isn’t square). The long, sculptured piazza is instead U-shaped and stands precisely above the first-century CE athletics track of the Flavian emperor Domitian.
Domitian built this stadium around 86 CE on land cleared by a devastating fire six years earlier. Known as the Circus Agonalis (after the Latin word for competitions ‘agones,’ it served mainly as a venue for athletic performances.
The stadium may, however, also have hosted gladiatorial contests, Christian executions, and, from its arcades which doubled up as brothels, some of the baser acts of everyday ancient life.
The present piazza gives a good sense of its dimensions. At 275 metres long, 106 metres wide and 30 metres high, Domitian’s stadium could accommodate 30,000 people.
The stadium gradually fell out of use until Late Antiquity, when its arcade was used to shelter the poor. Its rubble was then robbed piecemeal over the centuries, recycled and incorporated into other building projects to become part of the fabric of Hidden Rome. Parts of the stadium are, however, pretty well preserved. You can still see its travertine arches beneath the I.N.A. Palace at the far end. The rest can be viewed by visiting the Stadium of Domitian.
Domitian’s Odeon
When the emperor Constantius II, Constantine the Great’s son, visited Rome in 357 CE, he was awestruck by one of the ancient city’s most widely recognised wonders: the Odeon of Domitian. According to the fourth-century CE writer Ammianus Marcellinus, Domitian’s Odeon was on a par with the Pantheon, Domitian’s Stadium, and, next on our list, the Theatre of Pompey in terms of its beauty.
The Odeon has now disappeared completely from sight, subsumed within hidden Rome, a victim of the historical ebbs and flows which have resulted in the haphazard preservation of Rome’s architectural legacy. But walk along the modern Corso Vittorio Emanuele and you’ll come across the curved façade of Palazzo Massimo alle Colonne. This palace’s curve was not a conscious architectural choice but took its shape from the building that belies it.
It is the stands specifically that give shape to the palace’s façade, designed to accommodate around 10,000 spectators who would flock to the Odeon for musical and theatrical performances. The Odeon resembled an extraordinarily beautiful ancient Greek theatre, as befit its function. As befit the man who built it, its construction was an expensive, populist gesture, which went down brilliantly with the people and sourly with Domitian’s rival aristocrats.
Other than the Odeon’s outline, preserved in the curvature of the palace’s façade, the only thing left of this remarkable structure of hidden Rome is a single cipollino column. It has certainly seen better days, and being situated in the centre of an inner-city car park you can’t help but fear for its longevity, especially given the devil-may-care nature of Roman driving. But for now it stands as a neglected vestige of one of Hidden Rome’s most remarkable monuments.
The Theatre of Pompey
Sheltered from the traffic of one of inner-city Rome’s busiest crossroads, the archaeological area around the Largo di Torre is one of the most curious ancient sites in the city centre. Its ruins are poorly signposted—so much so that most people survey them only to spot the cat sanctuary.
But it was here, on the level below this busy intersection, that Julius Caesar was assassinated.
On the Ides of March 44 BC, the great dictator met his bloody end in the newly built Senate house annexed to the theatre of his great rival Pompey Magnus. Here, beneath a statue of Pompey, he was stabbed 23 times in one of history’s most famous (and most botched) assassinations, ushering in the death of the Republic and the birth of the Roman Empire.
Though archaeologists believe they have identified the spot where Caesar was killed, nothing remains of his rival’s 17,500-capacity theatre annexed onto the site. This is all the more surprising given its historical significance. For, as the first permanent stone theatre in Rome, the Theatre of Pompey was one of the defining monuments of the late Republic.
Funded from the proceeds of Pompey’s many wars, the theatre was incredibly symbolic: a populist political gesture aimed at getting the people onside by building for them a state-of-the-art public venue.
Building stone entertainment arenas in the city was, in fact, politically prohibited, partly because the Romans feared such populist gestures and partly out of a general disdain for much of the arts. Pompey was only able to circumvent this prohibition because he could claim it was a stairway leading to the Temple of Venus “Victory” at the top (which, technically speaking, it was).
The Theatre of Pompey may be invisible on the surface, but in terms of Rome’s topography, it is one of the best examples of urban continuity in the city.
Completed in 55 BC, it was restored numerous times over the centuries following fires and other natural disasters before being built over entirely. But the shape and size of its large curve are perfectly evident from the bend in the buildings above it on the Piazza di Grotta Pinta. Making the enormous Theatre of Pompey a true topographical mammoth of hidden Rome.
Ludus Magnus
All year round, people gather outside the Colosseum to marvel, line up and get photos in front of the most famous monument in Italy. But you should also make the time to visit its surrounding neighbours, each of which offers its own unique insight into Rome’s incredible past.
Just a few minutes walk east of the Colosseum, concealed beneath the modern street level of the Via Labicana and the Via di San Giovanni in Laterano, is the Ludus Magnus: the largest of four gladiatorial training schools built in the area around the Colosseum.
On the left is the gladiators’ living quarters; on the right what remains of their training amphitheatre, the eastern part forever lost beneath Via San Giovanni as part of hidden Rome.
Built by the emperor Domitian (81 – 96 CE), whose family, the Flavians, constructed the Colosseum, the Ludus Magnus was a multipurpose facility serving as the residence and training centre of the Colosseum’s gladiators. It housed staff too: trainers, administrators, cooks, surgeons and (where surgery failed) morticians.
Only one of its original three stories of accommodation cells survives, though even this is enough to give you a sense of scale for the living quarters alone (each cell housed up to five men). More eye-catching, however, is the section of a small amphitheatre where the gladiators used to train and vague traces of its cavea (seating area), spacious enough for 3,000.
Much of the amphitheatre and the Ludus Magnus is lost. Irrecoverably built over by the modern road and thus consigned to memory as a monument of hidden Rome. Were it not for archaeological efforts in the twentieth century, we would be none the wiser that the Ludus Magnus was once directly connected to the Colosseum via a long (and regrettably no longer accessible) tunnel.
Meta Sudans
Our last hidden Rome relic takes us outside the Colosseum to the junction between the Arch of Constantine and the beginning of the Via Sacra and the Roman Forum. All that remains are its concrete foundations, cut into a grassy mound, barely drawing a second’s glance from passing visitors.
But in its day, from its construction during the reign of Titus (79 – 81 CE), it was a 20-metre high conical fountain, with a width of 16 metres, standing in a pool 1.4 metres deep, and designed so it seemed to sweat water (hence its name, Meta Sudans, which means “sweating meta” in Latin).
Traditionally, a meta was the conical structure that stood at either end of chariot-racing tracks and marked the point the charioteers had to steer around. The Meta Sudans served a similarly pivotal purpose. Only it featured at an event that carried far more prestige (and at a significantly slower speed).
Standing in the back of a chariot, dressed up as Jupiter, with a slave behind him whispering a reminder in his ear that he was only mortal, a victorious general would pivot around the Meta Sudans during his triumphal procession over a vanquished enemy.
He would have come from the Via Triumphalis, its streets lined with adulating crowds hoping to be showered with spoils and plunder from his victorious campaign. From the Meta Sudans, he would make his way up the Via Sacra into the Roman Forum and toward the climax of his triumphal parade at the Temple of Jupiter Optimus Maximus.
The Meta Sudans languished in a state of disrepair until the modern age. So much so that by the twentieth century, and the dictatorship of Mussolini, only its brick core survived. Then, in 1936, Il Duce had it hurriedly razed to create space for Fascist parades around the Via dei Fori Imperiali.
It was only in the 1980s that its overlooked concrete foundations were excavated. Pointing sharp-eyed travellers to a fascinating relic of hidden Rome.
