The excavations, begun in 2003, aimed to check the relationship of the early medieval and medieval settlement of Piana San Marco with the Roman and Italic sites in the area and acquire information regarding the nature of the first monastic nucleus and the successive structural transformations, in addition to defining the site’s chronology and topography.
The 2016 excavations had two main objectives:
1. To define the chronological phases of the church of San Marco and investigate a wall that was identified in the north-west corner of the church during previous excavations. The structure is constituted by several limestone blocks jutting out of the section forming the edge of the excavation area (USM 1186) and a floor surface of large tiles (USM 1283), in both cases reused materials from the adjacent Italic-Roman temple (fig. 1);
2. The reconstruction of the line of the settlement’s perimeter wall, which was partially excavated and exposed during previous campaigns.
Therefore, in the first case, excavation was renewed inside the church (Area 5), while in the second case, work continued in the trial trench opened in 2014 outside the church, on the south and south-eastern sides of the complex (Area 9) (fig. 2).
A small sondage measuring 3.30 × 2.10 m, a surface area of 6.468 m2, was opened inside the church close to the north-western corner (fig. 3). Here, the stratigraphy suggested that the area underwent substantial structural modifications during the centuries, mainly involving the destruction and removal of the original structures or at least part of them. This would seem to be shown by the razing of wall USM 1186 and the large cut US 1176, which extended along most of the south-west side of the church, but primarily by the installation of two lateral pillars USM 976-977 on which an architrave, no longer existing, was probably mounted. Lastly, the layers filling the cuts and voids left by the removal of the earliest layers and structures provoked a general rise in the floor level on which, in the modern period, the floor relating to the last phase of the church of San Marco as a cult building, was built.

As regards the external perimeter wall of the settlement, the 2016 campaign identified the rest of the structure, which runs on an east-west alignment, and documented the fact that at a certain point it turned a 90° corner to the north. This led it to join with the remains of another section of standing wall, which begins at the south-western front of the architectural complex of San Marco (fig. 4). Thanks to this work, it was finally possible to reconstruct the development and line of the settlement’s perimeter wall and to gain a more precise idea of what must have been the limits of the site itself.