Underground the modern city of Rome there is a whole universe to explore! Ancient ruins, secret temples, catacombs. Some of these sites are huge, others are small and can be visited in just about 5 minutes. However, in any case you’ll get that feeling of excitement just by taking the first few steps down.

You’re uncovering the unknown, you’re setting on an adventure through the places that most people don’t see or don’t make the effort to find, because they are concentrated on what’s on the surface.

But how many times have you wondered, why is Ancient Rome underground? Has it always been like that? Is it due to earthquakes, disasters, or something else? Keep reading to find out.

The various reasons why Ancient Rome is underground today

There are a lot of underground sites in Rome, originating from many different situations. Some of them were intended to be underground since the beginning, others ended up being underground through the centuries.

For example, the catacombs, were underground since the very beginning to overcome a matter of space.

Other ancient ruins within the city center instead, appear in a street level which is lower than the modern city street level, but they were originally entirely overground. This is because the ground level raised through the centuries. But why?

The ground level raised through the centuries

For many centuries Rome suffered the flooding of the Tiber river. This kept happening since the very beginning of Rome until the end of the 1800s, when containing walls were eventually built to contain the waters (the walls that you can see today on the sides of the river).

The ancient Romans overcame part of the problem by building a sewage system which drained the heart of the city, the Roman Forum. This sewage system is called Cloaca Maxima. You won’t believe this, but this ancient sewage system still works today, draining the water from the Roman forum and releasing it into the Tiber river.

This sewage system stopped working after the Roman empire fell, and the area of the Roman Forum became often filled with debris and dirt brought by the river during its flooding. The dirt and debris accumulated, and the ground level raised over time.

Not only the river, but also human intervention contributed in raising the ground level. In fact, during the middle ages (after the Roman Empire) the city center developed somewhere else. The city center was not anymore in the area of the Roman Forum (as it was in ancient Rome) but it was rebuilt in what we call today the Centro Storico (Historical Center). That is the area of the Pantheon and Piazza Navona.

New constructions required excavations. And where was the ground resulted in that excavation dropped? In the area of the “old” city center, the area of the forums, which were abandoned and used as lands for pastures. That’s how the ground level raised through the centuries in this area.

Ancient Roman ruins used as foundations for new buildings

Have you ever heard of how the Ancient Roman buildings still stand today, while the modern buildings fall apart after a few decades? The Ancient Roman buildings were so well made, sturdy and resistant. And hard to demolish. The Roman inhabitants of the middle ages realized that.

So why putting so much effort in demolishing the Ancient Roman buildings, while they could just build on top of them and use them as strong foundations? This would also elevate their height and have the buildings in a higher position with respect to the Tiber river, that kept flooding the city. Therefore the overground buildings of ancient Rome became underground foundations to the following buildings.

A fitting example for that is Piazza Navona. Have you ever noticed its hairpin shape? That is due to the fact the ruins of the Ancient Roman Stadium of Domitian were utilized as foundations to the following buildings. The spectators seats of this stadium are now underground the buildings framing this beautiful square.

You can still see today the ruins of the Stadium of Domitian underground Piazza Navona.

Want to discover some underground sites of Rome? We wrote a list of our favorites here. And if you wish to explore these places with us, have a look at our guided Rome experiences. We take you underground the Trevi fountain, underground Piazza Navona, underground Trastevere and in the catacombs!