5 STRANGE Roman Buildings you didn't Know Existed

The Roman Empire was stranger than most people realize, and they built some of the most unusual looking structures around. The Pyramid of Sestius in Rome, Italy You're stepping off the metro in Rome, somewhere south of the Circus Maximus, and you turn a corner into ordinary city traffic with scooters, buses, pedestrians, and there, wedged between a busy intersection and the city walls, is a perfect white pyramid. 36 meters tall, 2,000 years old, completely intact. This is the Pyramid of Sestius, built between 18 and 12 BCE as the tomb of a Roman magistrate named Gaius Sestius. He was a praetor, a tribune of the people, and a member of a priestly college responsible for organizing sacred banquets in honor of the gods. He was not, by any account, a pharaoh, but this was the height of Rome's obsession with all things Egyptian. In 30 BCE, Octavian had conquered Egypt, Cleopatra was dead, and overnight, Egyptian culture became the most fashionable thing in the Roman world. Obelisks, temples, exotic aesthetics, rich Romans started building pyramids for their tombs. Sestius went a bit further than most. He specified in his will that the monument had to be completed in exactly 330 days, and threatened to withhold the inheritance from his heirs if they missed the deadline. They made it, of course. What makes the pyramid strange, though, even by Egyptian standards, is its shape. It wasn't modeled on the famous Pyramids of Giza. The steep, sharply pointed form was copied from Nubian pyramids, from the kingdom of Meroe in modern Sudan, which Roman attacked in 23 BCE. Sestius may have served in that campaign, and the pyramids as we see it today is almost certainly a commemorative act of personal vanity dressed up as architecture. The pyramid survived because later emperors incorporated it into the Aurelian Walls as a corner bastion, and making it structurally irreplaceable. For centuries, people forgot who built it and assumed it was the tomb of Remus, twin brother of Romulus. The real inscription was only rediscovered in excavations in the 1660s, and today it stands, perfect and preposterous, next to a metro station named after it, while the trams run by and thousands of Romans commute past a pyramid every day without even looking up. 4. The Arch of Janus Most people who visit Rome know what a Roman triumphal arch looks like. They've seen the Arch of Titus or the Arch of Constantine near the Colosseum, single-span monuments celebrating military victories covered in relief sculptures depicting conquered peoples and processions of soldiers. What almost nobody knows exists is the only Roman arch in the world built on an entirely different principle, one that faces four directions simultaneously. The Arch of Janus stands in a quiet corner of the old Forum Boreum, Rome's ancient cattle market near the Circus Maximus, and largely overlooked by tourist routes. It is a quadrifrons, a four-faced arch, meaning that it has a separate archway on each of its four sides, arranged around a central square vault so that anyone approaching from any direction can pass through. No other arch of its kind has survived from antiquity. In a city full of arches, this is the only one that does something architecturally different from all the others. It was built in the 4th century AD, most likely during the reign of Emperor Constantine or his sons. The most recent scholarship based on reconstructed inscription fragments points to 357 AD and Constantius II, despite its imposing scale. 16 meters high, built from a core of brick face with a marble strip from earlier buildings. Nobody knows with any certainty what it was for though. It doesn't celebrate a victory. It's got no carved reliefs or battle scenes. Its 48 niches arranged in two rows around its four piers are all empty. Whatever statues once stood in them are long gone. The name Janus didn't even attach itself to the structure until the Renaissance. It was not called that in antiquity. The theories for its purpose do range from the practical to the symbolic. Some scholars argue it was simply a covered market shelter, a monumental awning for cattle traders doing deals in the rain. Others believed it was a boundary marker where two districts of the city officially met. The most satisfying explanation though may simply be that it stood at a genuine crossroads above the Cloaca Maximum, Rome's great sewer running beneath, and served as an architectural statement about Rome's dominance over the movement of goods, people, and ideas from every direction. In the Middle Ages, the Frangipane family fortified it as a private tower. In 1830, archaeologists removed what they thought was a medieval addition to the top, an attic story, only to later realize it was original. The arch stands today missing a significant portion of itself. It's closed to visitors since a nearby bombing in 1993, and wears its mystery on the outside for anyone who bothers to stop and look. 3. The Temple of Hercules Victor There's a building standing in Rome right now that's older than the Forum, older than the Colosseum, older than most everything that typical visitors see. A circular marble temple so well preserved that it looks, from certain angles, like it was built last century. Most tourists walk straight past it. It sits about 60 meters from the famous Mouth of Truth in a small park beside the Tiber, and the tour buses stop right next to it without stopping for it. Buses line up to see a stone face in a church wall. Across the road, the old marble building in Rome stands quietly in a ring of ancient columns, attracting almost no one. The Temple of Hercules Victor was built in the late 2nd century BCE, around 120 BCE, making it somewhere over 2100 years old. It is the earliest surviving marble structure in Rome, and crucially, the only surviving building in Rome made not from local Italian marble, but from Pentelic marble, the same stone used for the Parthenon in Athens. This makes it not just architecturally extraordinary, but historically important. A Roman building constructed from Greek marble by what is believed to have been a Greek architect, Hermodorus of Salamis, using materials either looted or purchased from Greece during Rome's conquest of the eastern Mediterranean. The form is a tholos, or a Greek-style circle temple, entirely surrounded by a ring of 20 Corinthian columns, all still standing except one. The columns employ what's known as entasis, a subtle curvature designed to correct the optical illusion that makes perfectly straight columns appear to bow inward. This is pretty sophisticated visual engineering for the 2nd century BCE, borrowed wholesale from Greek practice. The circular design caused centuries of confusion for most of the medieval period. Everyone assumed this was a temple of Vesta, the goddess of the hearth, because her temples were also circular. It wasn't correctly identified as a temple of Hercules until Napoleon's prefect of Rome figured it out in the early 19th century. Nobody knows for certain who commissioned it. One theory credits Lucius Mummius, the Roman general who sacked Corinth in 146 BCE and brought enormous quantities of Greek art and materials back to Rome, in which case the marble itself would have been war spoils. A competing theory credits Marcus Octavius Horrenus as a wealthy merchant who supposedly built it in gratitude after Hercules saved him from pirates at sea. The merchant theory is charming, the general theory is more plausible, the answer is lost though. What's not lost though is the temple itself. 19 of its 20 original columns are still standing. The cellar wall survives and there's even a fresco inside, the medieval Madonna, from the period when it served as a church dedicated to the first Saint Stephen, then briefly to Saint Mary of the Sun. Somewhere along the way someone decided to name it the Temple of the Sun and it made sense because an image of the Virgin had been found nearby and was thought to glow. Well, the ancient Romans would have found this baffling, also surviving the local folk belief, still occasionally repeated, that neither flies nor dogs will enter the temple. That's been never tested systematically though. 2. The Domus Aurea In the year 64 AD, a catastrophic fire swept through Rome, destroying entire neighborhoods across the center of the city. The ancient sources are divided on whether Emperor Nero started it deliberately, but what's not disputed is what he did immediately afterward. He seized the charred land and began constructing on the scorched hillsides between the Palatine, Esquiline, and Caelian hills, the most extravagant private building complex in the history of the ancient world. When it was finished, Nero looked around at the gold leaf walls, the artificial lake big enough for a naval battle, the rotating dining room ceiling that rained perfume and rose petals onto the guests below, the statue of himself 35 meters tall at the entrance, and said, according to the historian Suetonius, that he was finally beginning to be housed like a human being. The Domus Aurea, the Golden House, a palace complex estimated at somewhere between 100 and 300 acres in the middle of Rome, with hundreds of rooms decorated in frescoes, mosaic ceilings, ivory inlay, semi-precious stones, and actual gold. The octagonal room, its architectural centerpiece, had a dome with an oculus open to the sky that predated, and almost certainly inspired, the Pantheon's design, built half a century later. The dining room above it had a mechanism that, operated by a team of slaves, caused the ceiling to rotate continuously like the heavens turning overhead. Nero was dead within four years of its completion. Forced to commit suicide in 68 AD, after the Senate declared him an enemy of the state, his successors moved with remarkable speed to erase his memory. The artificial lake was drained, the Colosseum was built on top of it, which is why its name comes from the Colossus of Nero, the enormous statue that stood at the entrance. The palace's gardens were open to the public, and the building itself was stripped of its marble and gold, its room filled with rubble and used as the foundations for the Bath of Trajan, built right on top of it. Within 40 years, the Golden House had entirely disappeared, and it would stay disappeared for over a thousand years. Then, sometime in the late 15th century, a young Roman fell through a crack in the ground on the Esquiline Hill and found himself in a strange cave covered in painted figures. Word spread quickly, soon the artists of early Renaissance Rome were lowering themselves into the underground rooms on ropes, Raphael, Michelangelo, and others crawling through Nero's buried halls with torches, sketching the extraordinary decorative frescoes still covering the walls in near-perfect preservation. The style they found, fantastic figures, mythological creatures, white backgrounds, they all became the foundational influence of Renaissance decorative art. The English word grotesque comes directly from these discoveries. The artists said it was like being in a grotto, a cave. Grotto gave them grotesque, and Raphael painted rooms in the Vatican, Michelangelo's chapel borders, decorative motifs across Renaissance Europe, all of it carries the DNA of Nero's buried dining room. Today, about 20% of the Domus Aurea had been excavated, the rooms are open to visitors, a former labyrinth of barrel-vaulted corridors and painted chambers beneath the Colle Opio Park, accessible only by a guided tour with a hardhat, of course. In 2019, archaeologists repairing a vault broke through a wall and found themselves staring at a completely undiscovered room covered in frescoes of panthers, centaurs, and sphinx. It's currently not open to the public and archaeologists are still working inside a room that Nero himself once walked through, and they're still finding things that nobody has seen in 2,000 years. Number 1. The Maritime Theater, Hadrian's Villa, Tivoli, Italy 20 miles outside Rome, in the hills above the town of Tivoli, there's a place that doesn't fit any category of building the Romans are supposed to have built. It's not a temple, or a bath, or a forum, or a palace, it's a circular island surrounded by a moat-like canal that's too narrow for any boat to navigate, accessible only by two small wooden bridges that could be drawn up on the inside to make it completely unreachable. It's a private island within an island, surrounded by a colonnade of ionic columns on both shores, with a small private residence at its center, containing everything one person could need to be entirely alone. It was built by an emperor at the height of his power. Its entire purpose was escape. The Maritime Theater is the most extraordinary room, or rather the most extraordinary not-a-room. This imperial complex outside Tivoli begun around 118 AD and expanded for the next two decades as Emperor Hadrian's primary residence and the effective center of the Roman Empire. The villa as a whole is staggering, 150 acres of ruins containing over 30 major buildings, baths, libraries, theaters, Egyptian-themed garden pools, a recreation of famous Greek landscape from Thessaly, underground tunnels for servants so they could move supplies without being seen. At its peak, it was larger than the city of Pompeii. Hadrian called it his ideal city. It was actually his private fiefdom, where he governed the empire between travels. But within all of that, within the most complex private estate ever built in the Roman world, the Maritime Theater stands apart as something personal and strange. It's not a theater at all, despite the name. It's a circular structure about 40 meters in diameter, built on an artificial island surrounded by a circular canal about four meters wide. The canal was crossed originally by two small rotating wooden bridges, which could be retracted from the inside, leaving the central island completely inaccessible. On the island is a small but complete miniature residence, rooms, a bath, a latrine, a kitchen, garden, a covered portico, everything necessary to live comfortably. Nothing necessary to receive anyone. Hadrian was a man of contradictions on an imperial scale. He traveled more than any Roman emperor before him. His reign was one long journey around the empire, from Britain to Egypt, from the Rhine to the Euphrates. He was intellectually restless, deeply interested in Greek philosophy and architecture, widely read, probably the designer of much of his own villa. And he was, by all accounts, someone for whom the noise of imperial court life was genuinely difficult. The Marine Theater was where he went when he needed to disappear. The emperor of the known world, surrounded by the of government, built himself a drawbridge island so he could occasionally be alone. The architecture does match the psychology. The colonnade of ionic columns running along both the outer and inner edge of the canal creates an extraordinary effect. The columns are reflected in the water on both sides. The island seems to float. The residence at the center has rooms designed to catch light at different hours of the day, suggesting Hadrian thought about where the fall in the morning versus the afternoon. There is evidence that the rooms were decorated with exceptional care, too. Though, like almost everything at the villa, the best decorations were stripped out centuries ago by cardinals and collectors. Cardinal Ippolito d'Este, building his own villa nearby in the 16th century, had removed statues, columns, and marble by the cartload. But what's left is still overwhelming. The basic structure of the Maritime Theater stands largely intact. The ring canal is still there. The position of the retractable bridges can still be identified. And when you stand at the outer colonnade and look in at the small circular island rising from the water with broken columns and overgrown stone in the light of the Lazio hills coming through the trees, you understand across 1900 years exactly what Hadrian was trying to do. He built the greatest private villa in the history of the empire. And then, inside it, he built somewhere to hide from it all. It is the most human thing in the most inhuman complex you'll ever walk through.