Cagliari, the capital of Sardinia, is a city that fascinates not only for its sunny beaches and historic seaside neighborhoods but also for an underground world rich in mystery and history.
Beneath the urban surface lies an intricate network of passages, caves, crypts, and tunnels that tell millennia of human stories. This “underground Cagliari” represents a parallel city, a buried realm of waterways, tombs, caverns, and air-raid shelters, winding for kilometers beneath the main historical districts like Castello, Marina, and Stampace.
Here, the sounds of daily life fade, making way for a silence broken only by the echo of ancient footsteps, where men and women buried their dead, sought refuge from wars, or invoked deities. Exploring these places means embarking on a journey through time, where historical reality and legends are inseparably intertwined, revealing a heritage often unknown even to the people of Cagliari.
Historical Origins: From Ancient Civilizations to Modern Shelters
The history of underground Cagliari is rooted in distant eras. The first traces date back to the Punic-Phoenician period, around the 8th century B.C., when these natural cavities were expanded to extract building materials, such as limestone blocks, used to build the city above. During Roman rule, these spaces took on new functions: aqueducts, cisterns, and necropolises. For example, the underground network included water management systems, with wells and channels that ensured the water supply for the population.
In the Middle Ages, under Pisan rule, more tunnels and wells were dug, such as the San Pancrazio Well in the Castello district, about 80 meters deep and built in the 1230s to supply the fortress. This well, accessible through a rock-cut tunnel, testifies to the engineering ingenuity of the time, even allowing for animals to operate the water wheel, the machine used to draw water.
With the arrival of the Piedmontese in the 18th century, the underground spaces acquired a military use: long tunnels were built, such as the Don Bosco Shelter, extending for about 180 meters, part of a defensive system along the northern side of the city. These structures, with their red brick arches, were later converted into air-raid shelters during World War II, offering protection to civilians during the Allied bombings of 1943. The underground city, with its 137 sites including quarries, cisterns, and crypts, became a life-saving labyrinth, where thousands of people found refuge among ancient frescoes and damp shadows. After the war, many of these places fell into disuse, but in recent decades, thanks to restoration and safety work, they have been reopened to the public, attracting visitors during events like “Open Monuments.”
The Main Sites: Crypts, Caves, and Tunnels
Among the most emblematic sites is the Crypt of Santa Restituta, in the Stampace district. This natural cave, expanded by man, has a troubled history: it was used as a Roman quarry, a Phoenician amphora depot, a place of pagan and then Christian worship, and finally a wartime shelter.
Dedicated to the Christian martyr Restituta, the crypt preserves traces of different eras, including Byzantine frescoes and ancient inscriptions.
Not far away, the Crypt of Sant’Efisio, beneath the church of the same name on Via Sant’Efisio, is linked to the tradition of the warrior saint, who was imprisoned here before his martyrdom in Nora in 303 A.D. It also served as a shelter during the war, connecting to pre-Christian cults.
In the Marina district, the Archaeological Area of Sant’Eulalia, discovered by chance in the 1990s, extends for 900 square meters beneath the church of the same name. Here, historical layers from the 4th century B.C. to the 19th century overlap: remains of a Punic temple, Roman paved roads, late-antique dwellings, and a water channeling system. The visit, often with tablets and audio guides, allows visitors to understand Cagliari’s urban evolution through foreign dominations.
On the slopes of the Castello hill, the Grotta della Vipera (Viper’s Cave) is a Roman funerary hypogeum from the 2nd century A.D., the tomb of Atilia Pomptilla and her husband Lucio Cassio Filippo. Part of a larger necropolis, the site includes poetic inscriptions that narrate the couple’s devotion. More mysterious is the underground lake beneath S’Avanzada, rich in archaeological history and legends, recently explored to uncover its origins.
Finally, the Crypt of Santa Maria Cathedral, in the Castello district, houses the Sanctuary of the Martyrs, with 179 niches dedicated to the saints, inaugurated in 1618. These places, often visitable with local guides, offer a unique experience, which can be extended to food and wine tastings or walks in the historic center.
Legends: Between Faith, Superstition, and Mysteries
Underground Cagliari is not just history; it’s also a melting pot of legends that intertwine reality and fantasy. In the Crypt of Santa Restituta, a 19th-century story tells of miraculous healings: during a smallpox epidemic, sick children would roll near the saint’s martyrdom column, believing that the dust would cure them. This mix of faith and superstition reflects the site’s use as a place of worship, where ancient pagan beliefs merged with Christianity.
The Grotta della Vipera is the subject of a tragic and romantic legend: Atilia Pomptilla offered her life to the gods to cure her husband of malaria, dying in his place. In the most remote corners of the underground spaces, stories are told of mysterious creatures that inhabit the depths, or of ghosts that haunt castles and tunnels, like the playful ones in the secret passages. The underground world is often described as a journey between light and shadow, enigmas and ancient myths, with tales of portals to the afterlife or hidden treasures. For example, the Don Bosco Shelter Tunnel evokes a mystical atmosphere, with legends linked to the bombings and lives saved in the darkness.
These narratives, passed down orally, add charm to guided tours, especially during events like Halloween, where the city’s spooky side is explored. The underground spaces, with their lakes and caverns, are rich in legends that reveal their archaeological and spiritual importance, such as the ghosts in the castles or the miraculous healings.
A Heritage to Discover
Underground Cagliari is a hidden treasure that combines millennial history and fascinating legends, offering a unique experience for tourists and locals. From wartime shelters to sacred crypts, every corner tells fragments of past lives, inviting reflection on the bond between man and earth. Visiting these places, often with expert guides, means not only exploring the past but also immersing yourself in an atmosphere dense with mystery. In a city like Cagliari, where the sun dominates, the subsoil reminds us that the true secrets are kept in the shadows.
If you want to take a tour of the mysteries of Underground Cagliari, trust Marcello Polastri.
