On the right aisle of the church a cave opens. This is what remains of a large complex of catacombs that used to develop in the vast surrounding area and, in particular, in the place formerly occupied by the Dominican convent. This quarry houses the three arcosolium tombs where according to tradition, two local noble women named Tecla and Giustina, who secretly took care of Saints Alfio, Filadelfo and Cirino during their captivity, buried their bodies after the martyrdom.
The tombs are divided into two areas. The smaller one has the only tomb with a fresco on the lunette, as well as a Greek period well. The fresco in the arcosolium bezel shows the archetypal representation of Deesis (from the greek "supplication", "intercession") and depicts the Christ Pantocrator with the Virgin Mary on the left and St. John Baptist on the right.
The representation is linked to Byzantine canons but has a dramatic charge, which is typical of the artistic production of the beginning of the 13th century.
Christ is frontally depicted with rounded brows and thick hair. A nimbus (halo) pearl surrounds his head. With his right hand he is blessing; while on the left hand he holds a red book on which a cross is placed. The red dress is largely covered by a blue/grey coat. The same color, invigorated in some parts by reddish tones and touches of white to shape the folds, can be seen on the clothing of the Virgin and St. John; both figures are facing the Christ.