The History of Preserving the Colosseum

The Colosseum has survived earthquakes, fires, abandonment, stone robbers, medieval builders, pollution, and finally, millions of visitors. Luckily, it was built for large crowds. Still, there is something strange about saying that the Colosseum has been “preserved.” For most of its history, nobody was actually trying to preserve it in the modern sense. Romans repaired it when it was damaged because they needed it, and Medieval Romans took stones from it because they needed those. A little later, they built homes and workshops inside it.

Only much later did people begin to look at the enormous ruin and decide that it was something that should be protected rather than used. The history of the Colosseum is therefore also the history of an idea. The idea that an ancient building should survive simply because it is ancient.

Built to Last

When the Colosseum was completed under Emperor Titus somewhere around 80 AD, nobody could have imagined that people would still be walking through it almost two thousand years later. To be honest, they probably didn’t think about it at all. Anyway, the Flavian Amphitheatre was enormous. Its four levels could accommodate tens of thousands of spectators, while beneath the arena floor was a complicated underground system of corridors, rooms, elevators and mechanisms used to stage the spectacles.

It was not designed as a monument to the distant past; it was a working building that required maintenance. Earthquakes damaged Rome several times during late antiquity. The Colosseum was among the monuments affected, and some of the damage was severe enough to require expensive repairs. An inscription discovered during excavations in the 19th century records restoration work carried out after an earthquake in AD 443. The repairs included the arena, podium, and seating areas.

In other words, the first chapter in the history of preserving the Colosseum was written by the Romans themselves. They repaired it because the building still mattered.

When the Games Ended

That eventually changed. The gladiatorial games were abolished in the 5th century, and the Colosseum slowly lost its original purpose. But it did not immediately become the ruin we know today. The building entered a new life. People continued to use its enormous spaces.

Some areas were occupied by workshops and houses. Other parts acquired religious functions. Burials appeared around the monument. The Colosseum was no longer an arena; it was becoming part of the medieval city, and that was both salvation and its destruction. A useful building had a reason to survive, but it also had something else that people wanted, and that something was stone.

The Colosseum Becomes a Quarry

For centuries, the Colosseum was treated partly as a gigantic source of building material.  The ruins were gradually dismantled and incorporated into the growing city. And that wasn’t vandalism; that’s just something that was happening all over the world. To a medieval builder, a large block of beautifully cut Roman travertine was an extremely useful piece of stone, sitting there waiting to be used.

The Archaeological Park of the Colosseum notes that the amphitheatre became a quarry during the Middle Ages and Renaissance, with material from it eventually contributing to buildings elsewhere in Rome, including St. Peter’s Basilica. The arena was being destroyed, but at the same time, parts of it were being given a second life.

People Lived Inside the Ruins

But besides being a quarry, the Colosseum also became a strange miniature neighborhood. Rooms and spaces inside the enormous structure were adapted for completely different purposes. Craft workshops appeared, and houses occupied parts of the building. The monument was repeatedly divided, modified, and reused. Today, this is particularly visible in the southern part of the Colosseum. Two enormous outer ambulatory rings eventually disappeared from this side of the building. 

As the Archaeological Park explains, the southern side accumulated a remarkable archaeological layer made up of centuries of collapse, stone-robbing, reuse and later construction. The Colosseum became a record of everything that had happened around it.

The Earthquakes That Changed the Colosseum

Some of the most dramatic damage was caused by something no Roman builder could control. Nature, especially earthquakes. As mentioned, the one in 443 AD was the problem for the Romans, but it wasn’t the only one. Rome experienced a series of major earthquakes during the 5th and 6th centuries. The Colosseum suffered serious damage to its seating, arena floor, service tunnels, and podium. But that wasn’t the end.

One of the most important events came in AD 847, when another major earthquake caused much of the already weakened southern side to collapse. The result was dramatic as an enormous section of the outer structure disappeared, leaving a vast heap of travertine.

But the earthquake did not create an untouched archaeological ruin. It created a new source of building material. People came and took the stones. It was a constant chain of destruction and reuse. First, nature brought parts of the building down, then people removed what nature had left behind.

 

The Moment People Started Looking at Ruins Differently

For centuries, the Colosseum was simply part of Rome, but then attitudes toward the ancient world began to change. During the Renaissance, scholars, artists, and architects became increasingly fascinated by ancient Rome. The ruins were no longer merely convenient sources of stone but the evidence of a lost civilization. Even travelers came to see them.

And gradually, the idea emerged that some ancient buildings should not simply be dismantled or adapted; they should be protected. Still, the Colosseum continued to suffer damage.

Saving a Ruin Without Making It New

Finally, by the 18th and 19th centuries, the Colosseum had become one of Europe’s most famous ancient monuments. But there was a problem. How do you preserve a building that is already partly destroyed? The main question was whether it is better to rebuild the missing sections or to leave it in its current condition and preserve it from further deterioration.

This question became central to the development of modern conservation. One of the most famous interventions came from architect Raffaele Stern, who constructed a massive brick buttress on the eastern side of the Colosseum in the early 19th century. Then came Giuseppe Valadier. His intervention on the western side, completed in 1826, created another enormous buttress designed to stabilize the surviving structure.

These attempts were made to prevent the remaining ancient structure from collapsing. The Colosseum was being preserved as a ruin.

The Colosseum Becomes an Archaeological Site

The next transformation was even more important. The monument was no longer simply something to look at; it became something to study, an archaeological site. Excavations revealed the underground areas.

The collapsed southern section became particularly valuable because the layers accumulated there preserved evidence from centuries of the monument’s later history, and this created a paradox. The destruction of the Colosseum had created some of the evidence needed to understand it.

What Does Preservation Mean Today?

Modern conservation is very different from the restoration projects of the 19th century, since the goal is not simply to make the Colosseum look impressive. It is to understand the monument, monitor its condition, and intervene when necessary without destroying the evidence that has survived.

Today, the Colosseum is maintained by a multidisciplinary team of restorers, archaeologists, architects, engineers, chemists, geologists and other specialists. The official archaeological park says that conservation work takes place throughout the year, from maintaining ancient travertine, tuff, marble, brick and mortar to dealing with vegetation, pollution, graffiti and structural problems.

And the problems never really end. There are many enemies. Rain enters the stone, temperature changes cause materials to expand and contract, plants can grow in cracks, pollution affects surfaces, and millions of visitors pass through the monument.

In 2024 alone, the Colosseum received around 14 million visitors. That is an extraordinary amount of human activity around a building that was already ancient when many modern cities did not yet exist.

Preserving It With Technology

Today, even the way we record the Colosseum is changing. The monument has a complete 3D survey and a Heritage Building Information Modeling system. Instead of relying only on drawings, photographs and written records, conservation teams can create a detailed digital representation of the monument and use it to monitor changes, plan interventions and better understand its structure.

The Colosseum contains thousands of individual elements, built, repaired, altered and reused over many centuries. Modern technology allows specialists to notice changes that might otherwise be difficult to see. And preservation has become increasingly preventive. Instead of waiting for something to collapse, specialists try to identify problems before they become emergencies.

A New Chapter for the Southern Colosseum

One of the most recent major projects illustrates how different modern preservation has become. Between 2022 and March 2026, archaeologists and conservation specialists worked on approximately 3,000 square meters of the southern area of the Colosseum. They excavated layers that had accumulated over centuries and found traces of the original pavement. They also documented the layers created after the collapse, including medieval reuse and later alterations.

The missing sections were not simply reconstructed as though nothing had happened. Instead, the new paving makes the original layout understandable while preserving the archaeological evidence of what disappeared. The result is not a new Colosseum, but a better explanation of the old one.

The purpose is not to turn the Colosseum back into AD 80. It is to make sure that what remains from AD 80, AD 443, the Middle Ages, the Renaissance, the 19th century and every period since then can continue to be studied.

Preserving Two Thousand Years of History

The Colosseum we see today is therefore not exactly the building the Romans saw. It is much more complicated. The ancient amphitheatre is still there, but with it, everything that happened between then and now is also there.

For almost two thousand years, people have changed it. Sometimes they damaged it, and sometimes they saved it. Sometimes both. Today, the Colosseum continues to be repaired, measured, studied, and watched, because there is still so much of what it was left to preserve.