Most people visit Italy for what stands above ground: the Colosseum, the canals of Venice, the towers of San Gimignano. But beneath the cobblestones and piazzas lies a different Italy entirely — one carved out over thousands of years by Romans, early Christians, medieval engineers, and volcanic forces. Italy’s underground sites are some of the most historically dense and genuinely surprising experiences the country offers.
This guide covers the main underground attractions across Italy, with practical information on what you will find, how to visit, and what to expect.
Naples Underground (Napoli Sotterranea)
Naples sits on top of a network of tunnels and chambers that stretches for roughly 80 kilometres beneath the city. Much of it was originally quarried by the ancient Greeks and later expanded by the Romans to extract tuff — a soft volcanic stone used as building material. The same tunnels later served as aqueducts, WWII air raid shelters, and, in some areas, a dumping ground that is still being excavated today.
Napoli Sotterranea, based near Piazza San Gaetano in the historic centre, runs the most accessible public tours. You descend about 40 metres below street level through narrow passages, some as tight as 50 centimetres wide. The temperature drops to around 15 degrees Celsius year-round, so a light jacket is useful regardless of the season. Tours last roughly 80 minutes and include wartime bunker chambers, ancient cisterns, and a section of the old Roman theatre beneath a residential building — where residents simply built their homes on top of the ruins rather than clearing them.
Separate from Napoli Sotterranea, the Bourbon Tunnel (Galleria Borbonica) offers a different slice of underground history. It was commissioned in 1853 by King Ferdinand II as an escape route from the Royal Palace to the military barracks. Construction was never completed, but the tunnel was repurposed as a bunker and later used to store vehicles and sculptures seized by police. Many of those objects — vintage cars, motorcycles, statues — are still there. Tours range from standard walks to kayak and adventure options through flooded sections.
Rome’s Catacombs
Rome has more than 60 known catacomb systems stretching along the ancient roads outside the city walls. They were used primarily as burial sites from the 2nd to 5th centuries AD. The word catacomb comes from the Latin catacumbas, referring to a specific hollow near the Appian Way. Early Christians used these tunnels to bury their dead and, during periods of persecution, to gather in relative safety.
The four main catacombs open to the public are those of San Callisto, San Sebastiano, Domitilla, and Priscilla. San Callisto is the largest and historically significant — it contains the Crypt of the Popes, where 16 early popes were buried. San Sebastiano is historically notable as a site where the remains of Saints Peter and Paul were temporarily kept. Domitilla contains the oldest known image of Christ as the Good Shepherd. Priscilla, on the other side of Rome, has the oldest known image of the Virgin Mary.
All catacomb visits are guided — independent access is not permitted. Tours move through galleries carved into volcanic tufa, passing burial niches cut into the walls in rows. The tunnels are dimly lit and the air is cool and damp. Visits typically take 30 to 45 minutes. Modest dress is required: covered shoulders and knees.
The Capuchin Catacombs of Palermo
Nothing quite prepares you for the Catacombs of the Capuchins in Palermo, Sicily. These are not ancient Roman burial sites but a later tradition that began in 1599 when Capuchin monks began preserving and displaying their dead rather than burying them in the conventional way. Over the following three centuries, wealthy Palermitans sought the honour of being interred here.
The result is 8,000 mummies displayed along the corridors, dressed in the clothes of their era and arranged by category: men, women, priests, surgeons, and children. The most famous is Rosalia Lombardo, a two-year-old girl who died in 1920 and was embalmed so successfully that she is known as the Sleeping Beauty. The catacombs are beneath the Convento dei Cappuccini near the Piazza Indipendenza. Entry costs a few euros; photography is restricted in some sections.
Orvieto Underground
The hilltop city of Orvieto in Umbria is built on a massive plug of volcanic tufa, and the Etruscans began tunnelling into it around 2,500 years ago. Today there are more than 1,200 known caves beneath the city, covering roughly 30,000 square metres. They were used for olive oil presses, wine storage, wells, dovecotes, and later as a refuge during medieval sieges.
Orvieto Underground runs regular tours departing from Piazza del Duomo, near the cathedral. The tours visit carved chambers, an Etruscan well, medieval pigeon houses, and a partially excavated pre-Roman section. Guides explain how each layer of use reflects a different period of Orvieto’s history. Tours last about an hour. The passages are low in some sections, so those with limited mobility or a sensitivity to confined spaces should check accessibility before booking.
Bologna’s Underground Canals
Bologna once had a network of canals that rivalled those of Amsterdam. Today almost all of them have been covered over and built on top, but a small section of the Canale delle Moline is accessible via a viewing window on Via Piella — a popular photo stop known locally as the little Venice of Bologna. More unusually, the city runs occasional tours that allow visitors to walk sections of the underground canals and see the medieval infrastructure that once powered Bologna’s textile industry.
The canals were used to drive the wheels of silk-weaving mills from the 12th century onwards. At peak production in the 13th century, there were more than 100 mills operating within the city. The underground sections preserve original mill machinery and brickwork. Tours are run by local operators and must be booked in advance; availability is limited.
Practical Tips for Visiting Underground Italy
Book ahead. Popular sites like Napoli Sotterranea and the Rome catacombs fill quickly in summer. Booking online at least a day in advance is advisable; for peak season, a week or more ahead is safer.
Dress appropriately. Underground sites are significantly cooler than street level, typically between 12 and 17 degrees Celsius. Bring an extra layer even in July or August. Wear flat shoes with a grip — surfaces are often uneven and can be slippery.
Check physical requirements. Some passages are narrow or require ducking. Most major sites provide this information on their websites. If you are travelling with young children or someone with limited mobility, it is worth confirming access conditions before you book.
Photography rules vary. Flash photography is generally prohibited in the catacombs. Some sites allow cameras without flash; others restrict photography entirely, particularly in sections with human remains.
Language. Guided tours are typically offered in Italian and English, sometimes French and German. Check the schedule on each site’s website before you visit, as English tours do not always run at every time slot.
Italy’s underground world is not a sideshow. It is where the country stores much of its oldest history — the layers that did not survive as monuments above ground, but were simply buried and forgotten until someone started digging again. If you have already seen the main sights and want something that requires more effort and offers more in return, this is where to start.
Secure Your Dream Italian Experience Before It’s Gone!
Planning a trip to Italy? Don’t let sold-out tours or overcrowded attractions spoil your adventure. Unmissable experiences like exploring the Colosseum, gliding through Venice on a gondola, or marvelling at the Sistine Chapel often book up fast—especially during peak travel seasons.
Booking in advance guarantees your place and ensures you can fully immerse yourself in the rich culture and breathtaking scenery without stress or disappointment. You’ll also free up time to explore Italy's hidden gems and savour those authentic moments that make your trip truly special.
Make the most of your journey—start planning today and secure those must-do experiences before they’re gone!