The 2012 investigations undertaken by the Centre Jean Bérard concentrated on the sector immediately outside the Porta Mediana, along the eastern edges of the basalt-paved area. The excavation, which aimed to define the development and topography of the necropolis, revealed the existence of four phases of use in the area, datable from the second half of the 2nd century B.C. to the early medieval period.

The earliest phase was attested by mausoleum D46, situated south-east of the Masseria del Procidiano. A dry-stone build of large, squared tufa blocks, it had one underground chamber. The monument was marked by the presence of three cippi inscribed in Oscan and Latin, which rested on the summit block of the façade.

The interior had a rectangular plan with a barrel vault. The chamber was occupied by two funerary couches and an a cassa tomb. The upper part of the walls was faced with white plaster and the lower part with red. The excavation identified at least three construction phases corresponding with the three burials.

The monument’s typology recalls a similar structure investigated in 2010, mausoleum D29. The latter had already been excavated in 1918 by canon de Jorio. Both tombs seemed to date to between the second half of the 2nd century and the first decades of the 1st century B.C.

The second phase was attested by a small mausoleum with underground chamber MSL46150, exposed in a trench east of mausoleum D46, within a large open cemetery area. The partially preserved tomb was quadrangular in plan and the interior walls were dry-stone built in opus quasi reticulatum. The funerary chamber had plastered walls and was arranged to house at least two funerary couches. Entry was via a door in the west wall.
During the third phase, corresponding with the construction of the via Domitiana in 95 A.D. and the reorganisation of the area in front of the Porta Mediana, a radical transformation of this part of the cemetery occurred. The earliest funerary monuments were obliterated and new structures built.

The first evidence for these interventions was the construction of monument D58, a structure of which only the large semi-interred funerary chamber was preserved intact. The exterior was built in opus reticulatum with toothing in tufa bricks, while the interior was in opus vittatum. The quadrangular chamber had a cross-vaulted ceiling. The excavation identified at least four construction phases. Originally, access to the chamber was from the south side. In a second phase, the construction of the columbarium D59, to the south-west, determined the obliteration of this entrance and the construction of a new one with steps on the north side.

Typologically, the mausoleum finds parallels in the 2nd century A.D. a tempietto tombs documented in the Via Latina necropolis in Rome. Excavation of the columbarium D59, situated between the Porta and mausoleum D58, brought to light important late antique and early medieval evidence.