Underground Rome: what to see beneath the city

May 20, 2026

What to see in underground Rome: water, catacombs, basilicas, ancient streets, and the Tomb of Aulus Hirtius in the hidden city.

Rome is a city built through successive layers, where two thousand years of history have left visible traces even below the current street level. The underground treasures of the Capital are not the result of a single urban project, but the outcome of fires, floods, reconstructions, and continuous reuse that transformed buildings, streets, and infrastructures into the foundations of the present city. Underground Rome reveals a parallel city made of water systems, places of worship, homes, and ancient public spaces. Water, in particular, plays a central role: canals, aqueducts, and cisterns still shape the underground landscape, as shown by the Euripus of the Campus Martius, the Tomb of Aulus Hirtius, and the Vicus Caprarius. Alongside these places, catacombs and layered basilicas reveal the religious dimension of subterranean Rome, while buried houses, streets, and monuments offer a glimpse into daily life in antiquity. Descending beneath Rome means crossing different historical eras within the same place.

TABLE OF CONTENTS

• Why there are underground treasures in Rome?
• Water beneath Rome: what to see
• Catacombs and underground basilicas in Rome
• Buried houses, streets, and monuments in Rome

Why there are underground treasures in Rome?

To understand the origin of Rome’s underground treasures, it is important to consider that the city is the result of two thousand years of construction sites, fires, collapses, invasions, reconstructions, and the gradual raising of street levels.

For more than two millennia, Rome has continuously been inhabited, transformed, rebuilt, and expanded. Each historical period left material traces that were not erased, but incorporated into later structures. This is why beneath the visible city there is a hidden Rome made of streets, buildings, canals, tombs, and places of worship that once stood at ground level.

Rome’s underground treasures are therefore not the result of a unified plan, but of a continuous historical process in which the city preferred layering over demolition.

In the ancient world, when a building lost its function, it was often reused as a foundation for new constructions or filled in to stabilize the ground. Floods of the Tiber River, fires, accumulated debris, and the progressive rise of street levels also contributed to burying entire districts over the centuries.

The result is a unique stratification in which the underground is not marginal, but an integral part of Rome’s urban history: a sort of parallel city that tells stories from different eras and has one constant protagonist: water.

Water beneath Rome: what to see

Water is one of the most powerful and least visible elements of underground Rome. The city developed thanks to an extraordinary hydraulic network made of aqueducts, canals, cisterns, and drainage systems, many of which still flow beneath the modern city.

Water was not only a resource, but also an organizing principle of urban space, and this becomes especially clear underground.

One of the most fascinating places where underground water plays a leading role is the archaeological area beneath Palazzo della Cancelleria, where a section of the ancient Euripus of the Campus Martius is preserved.

The Euripus was a monumental Roman canal and part of a complex hydraulic system that crossed one of the most important areas of ancient Rome. Today, changes in the terrain and later urban transformations have turned the canal into a large underground cavity where water gathers and reflects the ancient structures. Within this extraordinary setting stands the Tomb of Aulus Hirtius, the Roman consul who died in 43 BC during the Battle of Modena.

The tomb was built by decree of the Senate in a prestigious area of the Campus Martius and is now partially surrounded by the waters of the Euripus, creating a striking visual atmosphere.

The Tomb of Aulus Hirtius can be visited through a route accessible from the rooms of the Leonardo Exhibition at Palazzo della Cancelleria, allowing visitors to enter a space that is not normally open to the public.

Another remarkable example of underground water in Rome is the Vicus Caprarius, also known as the City of Water, located near the Trevi Fountain. Here visitors can observe Roman structures connected to the management and distribution of water, supplied by the Aqua Virgo, one of the ancient aqueducts still functioning today.

In this site, water becomes the element linking Imperial Rome to the contemporary city, demonstrating how hydraulic infrastructures ensured urban continuity for centuries.

Catacombs and underground basilicas in Rome

In ancient Rome, it was forbidden to bury the dead within the city walls, leading to the development of large underground necropolises along the consular roads. This is why catacombs are among the best-known but also most complex aspects of subterranean Rome.

They are true underground urban landscapes created to respond to religious, social, and legal needs.

Christian catacombs such as those of Saint Callixtus or Domitilla tell the story of a Rome made of communities, symbols, rituals, and memory. Corridors carved into tuff stone, overlapping tombs, frescoes, and inscriptions create an atmosphere that is both intimate and collective.

Alongside the catacombs, underground Rome also preserves layered basilicas whose lower levels contain older structures. One example is the Basilica of San Clemente, where visitors can descend beneath the medieval church to discover an early Christian basilica and, even deeper, Roman rooms and a Mithraeum.

Another important underground basilica is San Crisogono in Trastevere, located near what was once known as the Etruscan bank of the Tiber.

In these places it becomes clear how Rome transformed itself over time without completely erasing the past. Underground religious Rome is therefore not only a place of devotion, but also a concrete testimony to the city’s ability to reuse spaces and adapt them to new functions and worldviews.

Buried houses, streets, and monuments in Rome

Beyond water systems and places of worship, underground Rome also preserves traces of daily life and public spaces from antiquity. Houses, shops, streets, and monuments that once stood at the center of the city are now located several meters below the modern urban level, offering a direct glimpse into inhabited ancient Rome.

The Domus Aurea, the vast palace commissioned by Nero after the fire of 64 AD, is one of the most impressive examples of how a monumental complex could become underground over time. Originally conceived as a luxurious residence surrounded by gardens and artificial lakes, the Domus Aurea was gradually buried and incorporated into later constructions.

Today, visiting the site allows people to explore spaces that deeply influenced Renaissance art and even the concept of decorated architectural space itself.

Another way to experience underground urban Rome is by visiting places where ancient streets and buildings emerge beneath modern squares and neighborhoods. In these contexts, visitors can clearly perceive how the city gradually “moved upward,” leaving beneath it entire fragments of urban life.

This underground Rome may appear less monumental than the great ruins above ground, but perhaps more authentic: a city made of lived-in spaces that were transformed, abandoned, and eventually buried, yet never completely forgotten.

You can read the Italian version of this article here >