Catacomb of Callixtus

The crypt fell into disuse and decay as the relics it contained were translated from the catacombs to the various churches of Rome; the final wave of translations from the crypt occurred under Pope Sergius II in the 9th century, primarily to San Silvestro in Capite, which unlike the Catacomb was within the Aurelian Walls.

A short distance away, an arcade dating to the end of the 2nd century gives access to the cubicula of the sacraments, with their frescoes from the first half of the 3rd century hinting at baptism, the Eucharist and the resurrection of the flesh; in the region of Saint Militiades next door, a child's sarcophagus has a front sculpted with biblical episodes.

Along "passage O" north of the Crypt of the Popes are, in succession, the crypt of the martyrs Calogerus and Parthenius and the double cubiculum of Severus, which contains a rhythmic inscription (dated to no later than 304) in which a bishop of Rome (at that time Marcellinus) is first called pope and first openly professes belief in the final resurrection.

In a region further from there, the so-called "Crypt of Lucina", is the burial of Pope Cornelius, whose tomb still has its original inscription giving him the title of martyr and, on its sides, splendid paintings with figures in 7th and 8th century Byzantine style representing popes Sixtus II and Cornelius and the African bishops Cyprian and Ottatus.

In a nearby cubiculum are some of the most ancient burials, after AD 175, with Roman frescoes of (on the ceiling) the Good Shepherd and orantes and (on the far wall) two fish with a basket of loaves behind it, a symbol of the Eucharist.