Cagliari, Crypt of Sant'Efisio

The hypogeum, dug deep into the limestone rock, is located in the historic district of Stampace. According to tradition, it is the prison where the holy warrior was tortured before being beheaded in Nora on January 15, 286 or 303.
The hypogeum is located 9 m below street level. It is accessed through a steep staircase that has its entrance from Via Sant'Efisio. The underground environment has a quadrangular plan, with irregular dimensions (14 x 11 m); the ceiling is held in the center by two pillars spared during excavation.
Leaning against a small apse carved into the wall and of the room, there is a marble altar decorated with Valencian “azulejo” dating back to the seventeenth century, still in excellent condition. Next to the altar is the column to which Saint Efisio was bound to suffer the scourging, because he refused to deny his Christian faith.
Perhaps already in the Punic era, the hypogeum was probably a quarry of limestone building blocks. According to some scholars, the underground environment was later used as a tank, a hypothesis rejected, however, by Antonio Taramelli, who noticed the total absence of waterproofing mortars spread on the walls to plaster them. Rather, he believed that it had been destined for the cult of the goddess Isis, based on the identification of a well dug into the floor, which would contain the mystical waters of the Nile, propitiatory to the rites of initiation.
When, in the 17th century, the interest in the search for the relics of saints and martyrs became increasingly vivid, the confreres of Sant'Efisio asked the religious authorities to also investigate the hypogeum, not already to find the remains of the warrior martyr, kept in Nora and stolen by the Pisans in 1088, but to search for the relics of other martyrs. In 1616, a burial dug into the dirt floor was found with a skeleton that the confreres attributed to the martyr Edizio, a soldier following Sant'Efisio. A few years later, the identification was confirmed by the discovery of an inscription on a marble slab (cm. 14 x 16) that read B.M. EDITIUS, or “Bonae Memoriae Editius”.
In modern times, the hypogeum was used by Cagliari as a refuge to escape the aerial bombing of the Second World War.

History of excavations
The hypogeum was investigated for the first time in the early twenties of the last century by Antonio Taramelli.

Bibliography
A. Taramelli, “Cagliari. Research in the crypt called the Sant'Efisio prison”, in News of the Excavations, 1926, pp. 446-456;
M. Dadea, “The prison of Sant'Efisio”, in Cagliari: urban itineraries between archeology and art, Cagliari, 1999, pp. 57-59;
A.M. Colavitti, Cagliari, series “Ancient Cities in Italy”, Rome, 2003, pp. 47-48.