Underground Italy, discovering the submerged heritage of caves, catacombs and ancient tombs

A halo of mystery shrouds the underground rooms of Cividale del Friuli, because the purpose of the Celtic Hypogeum has not yet been established by historians.

Probably used as a burial place in the Celtic period, or as a prison in the Roman or Longobard period, it consists of a room excavated in the rock seven metres underground.

As you wander through the various tunnels, look out for the three masks and be fascinated by the many questions they raise.

The Lombard city offers an original underground experience of urban potholing.

Cremona has underground ice-houses, air-raid shelters, crypts, a network of canals and tunnels: a truly unimaginable itinerary.

An unmissable stop on this tour is the 17th-century hypogeum beneath the Church of Sant'Abbondio, built for the burial of members of the Teatini religious community. We advise you not to miss the tempera drawings that decorate the walls. They are truly astonishing.

Visits to the city's fascinating underground passages only take place on certain dates during the year, and by guided tour. Before you set off, check the information on the Cremona Underground website.

There are several stops on the tour of underground Turin.

Among catacombs under churches, the cellars of Baroque palaces, the ice houses of Porta Palazzo, the air raid shelter used during World War II: for about three hours you will pass through the tunnels that wind beneath the surface of the city. These tunnels were mostly dug in 1706, when Turin was besieged by the French.

Don't miss a visit to what remains, hidden in the belly of the earth, of an entire fortified citadel, of which only the keep remains today under the open sky. It can be accessed from what is now the Pietro Micca Museum.

The capital hidden in the belly of the earth has no less grandeur than the one on the surface: it is an authentic, immense treasure chest, a parallel world.

There is the Rome of Augustus, down there, the underground area of the Imperial Forums and the famous catacombs. Every basilica, in its foundations, has its other side: such as San Giovanni in Laterano, where you descend six metres underground, and the Church of Santa Maria Maggiore with the remains of a thermal spa. And dozens of domus under as many churches and the Etruscan aqueduct.

If you want to do something special, you can also organise private tours a little in advance. And Rome, seen in this way, will be even more special.

There are 15 places of art and history submerged in the Apulian city. In Taranto, the remains of the Old Town from the year 1000 conceal cellars, oil mills and granaries of ancient palaces, convents and churches.

The Frantoio Ipogeo Normanno (Norman Hypogeum Oil Mill) is one of the oldest in Apulia, preserving the original millstones as evidence of a tradition that has survived to the present day. The Hypogeum of Palazzo Baffi, on the other hand, is the deepest in the city. It consists of two main rooms and has a vast network of tunnels, some of which lead to the sea, others to the Aragonese Castle and still others to Piazzetta San Francesco. The one in Palazzo Arco Paisiello, on the other hand, is the most architecturally interesting hypogeum. To plan a visit, just enquire at the Apulia Region Tourist Office.

There is much to see some 40 metres under the alleyways of Campania's capital city. There are finds from the Greek and Roman city, and the World War II tunnels where 40,000 Neapolitans took refuge to escape the bombings.

The Galleria Borbonica offers an adventure tour of the underground city of Naples, where, armed with a helmet and torch, you can visit the cisterns passing under the 18th-century arches; the last section is taken by raft, along the water table.

Next, explore the Catacombs of San Gennaro and those of San Gaudioso

Like so much in the city, Naples' underground world harbours fascinating stories, myths and legends. Are you familiar with the figure of the 'Monaciello' or 'Munaciello'? The story of these spirits, sometimes benevolent, sometimes malevolent, represented as little boys small in stature and dressed in a monk's habit, is closely linked to underground Naples.

Legend has it, in fact, that they were professionals who looked after the city's water supply, but since they had free access to all the houses through the wells, they were more interested in the housewives than in the aqueduct.

Before venturing out to discover underground Naples, it’s a good idea to buy your ticket online to avoid long queues and waits.

Sicily is also an area that lends itself to visits to sensational underground sites.

In Palermo, there are the 2,000-year-old Palaeo-Christian Catacombs of Porta D'Ossuna, and the labyrinth of the qanats, once tunnels that formed the complex water system built by the Arabs.

For a macabre thrill, the place to go is the Capuchin Catacombs, where you will be greeted by hundreds of perfectly preserved mummies.

To plan your visit: various tours can be booked on archaeofficina.com with fee-based guided tours.

For the Capuchin Catacombs, the chargeable entrance is every day from 9 a.m. to 12:30 and from 15:00 to 17:30.

With a visit to the extraordinary Valley of the Temples, one enters the upside-down world of the Sicilian city that is the guardian of one of the most significant archaeological sites in the world.

The Valley of the Temples Park is home to an authentic archaeological and scenic jewel. Accompanied by experienced speleologists, you will descend into the Kolymbetra-Porta V Hypogeum, and then take an easy route to the Giacatello district for a visit to the Hypogeum of the same name, amidst conduits, tunnels and cisterns.

Open to everyone, adults and children alike, as long as they have plenty of curiosity, more than a visit it is a remarkable journey into the bowels of our earth and our history.

Underground cities, mirrors of past civilisations, give our country a precious heritage that not only enriches us culturally, but also allows us to discover hidden treasures of inestimable value.