The necropolis occupies the western slopes of the Bonaria hill.
Bonaria's funerary vocation dates back to the 4th century BC, when, in the middle of the Punic Age, the hill was used as a burial place. Today, nothing is preserved from this oldest phase, while the Roman tombs remain. From the first century AD, numerous burial cubicles were excavated, with arcosols intended to house sarcophagi and niches for burial urns. A large number of simple pit tombs, on the other hand, extended in the area at the foot of the hill, towards O, coming to join the necropolis on which the Basilica of San Saturnino was built.
During the work carried out in 1888 to expand the monumental cemetery of Bonaria, two funerary cubicles decorated with frescoes related to Christian symbolism came to light on the O slopes of the hill. The largest cubicle, entirely carved into the rock, has arcosols on the walls and some pits in the floor. A marble slab, walled into the wall of one of the arcosols, bore the epitaph of Munazius Irenaeus. The same wall was decorated with figures of peacocks, a symbol of immortality, while in the basement there were two scenes from the life of Jesus, perhaps the miracle of the paralytic and the resurrection of Lazarus. These paintings, now completely disappeared, have been dated to the beginning of the 4th century AD.
Not far from Munazius Irenaeus's cubicle is the so-called Jonah cubicle, now in a very poor state of preservation. This burial is partly dug into the rock and partly built with bricks plastered with lime. Inside there were some sarcophagi and wall frescoes depicting episodes from the life of the prophet Jonah. In particular, the scene on the back wall showed two Roman ships, of which the first is a symbol of the Church Ship, with the Apostles fishing men, while from the second boat some men throw Jonah into the sea, who, swallowed by the sea monster, is thrown up, after three days, on the beach, foreshadowing the resurrection of Christ. Finally, on the right wall of the cubicle, a bucolic landscape was painted, where a flock grazed among the vegetation, watched over by a shepherd with a sheep on his shoulders, an obvious allusion to Christ the Good Shepherd. Even these frescoes, dating back to the first half of the 4th century AD, are known only through watercolors made in the nineteenth century.
During the excavations in 1987, three landfill pits were identified in the part of the medieval imperial necropolis, which cut through the decking of the Roman burial area. In particular, one of these three pits has returned, in addition to large quantities of ceramic fragments of various types, numerous fragments of amphorae. Graffiti (Greek and Latin letters) are engraved on the surface of most of the amphorae, allowing them to be dated to a period between the 7th and 8th centuries AD.

History of excavations
In 1587, about thirty tombs were investigated inside the church of San Bardilio, which was located near the current direction of the Bonaria Cemetery. Various excavations affected the area especially during the nineteenth century, during the work for the construction of the new cemetery. The last excavations date back to 1987, by the Archaeological Superintendence for the provinces of Cagliari and Oristano.

Bibliography
F. Vivanet, “Christian catacombs of Cagliari, discovered in the hill of Bonaria, near the current cemetery”, in News of the Excavations, 1892, pp. 183-189;
L. Pani Ermini, “Notes on some cubicles of the ancient Christian cemetery of Bonaria in Cagliari”, in Studi Sardi, XX, 1968, pp. 152-166; D. Salvi, “The Eastern Necropolis”, in D. Mureddu-D. Salvi-G. Stefani, Sancti Innumerabiles, Oristano, S'Alvure, 1988, pp. 79-83;
A.M. Nieddu, “Early Christian Painting in Sardinia: New Acquisitions”, in Journal of Christian Archaeology, LXXII, 1996, 1-2, pp. 245-283; M. Dadea, “The Necropolis of Bonaria”, in M. Dadea-S.
Mereu-M.A. Serra, Archdiocese of Cagliari, series “Churches and Sacred Art in Sardinia”, Cagliari, Zonza, 2000, pp. 219-220;
D. Mureddu, “Cagliari, the area adjacent to the Bonaria cemetery: an early medieval waste with globular body amphorae”, in On the Edge of the Empire. History, art and archeology of Byzantine Sardinia, curated by P. Corrias-S. Cosentino, Cagliari, M&T Sardegna, 2002, pp. 237-241;
A.M. Nieddu, “Paleochristian art in Sardinia: painting”, in Insulae Christi. Primitive Christianity in Sardinia, Corsica and the Balearic Islands, edited by P.G. Spanu, Oristano, S'Alvure, 2002, pp. 366-386.