During the third campaign excavations were carried out to the south-east of the zone investigated in 2008 and 2009. This area is behind the Pisan tower where, among the vegetation of agave and Mediterranean maquis, part of a wall was visible. The excavation uncovered a rectangular structure on a north-west/south-east alignment. Two of the long sides and part of the short north-west side were preserved, while the short south-east wall is still hidden by vegetation and will be investigated in the future. The structure was c. 13 m long and 6.80 m wide, with a side entrance, perhaps secondary, with two steps leading to the interior.

Inside the structure were the remains of a floor of square terracotta tiles and a bench running along the north-west wall. The situation on the other side is not yet clear apart from the presence of pillars, one of which in situ although it had collapsed across the room.

The perimeter walls were preserved to a maximum of one metre in height and traces of plaster were still visible.

The building had collapsed towards the south-east, as attested by the perimeter wall that had fallen outwards (but lay still intact presenting a height of 4.80 m and 4.70 m in width) and the pillar mentioned above.

In the southern part of the excavation, an alignment of three large ashlar blocks and part of a lime floor surface were uncovered, which appeared to be connected with a similar situation identified further north during preceding campaigns. This may represent the organisation of the area prior to the construction of the rectangular building consisting of a large paved area delimited by a large wall that extended as far as the structure, situated at about 30 m further north. Future excavations will attempt to clarify the relationship between this floor, the large ashlar blocks and the rectangular structure which, although much later that the first two, seems to have incorporated them in some way.

The rectangular building could perhaps be interpreted as part of the church of S. Elia al Monte, in its final phase of restructuring dating to the 17th century, funded by the inhabitants of Quartu Sant’Elena, and attested by a manuscript of 1720. This dating was also confirmed by the excavation finds.
The manuscript also mentions the destruction of the church: “despues al año 1717 fuè d(ich)a ig(lesi)a devastada delos españoles q(ui) entraron en Caller a fuerza de armas; y non dexaron mas q(ue) las paredes…” (I. Farci, Quartu Sant’Elena. Arte religiosa dal Medioevo al Novecento, Cagliari 1988, pp. 187-188).