As part of the archaeological investigations aimed to render more attractive the remains of the medieval cathedral of Santa Maria Assunta in the Priamàr architectural complex, excavations were undertaken by the International Institute of Ligurian Studies and Genoa University. This campaign concentrated on the area situated south-west of the nave (brought to light during the 2008-2009 campaigns). In fact, according to the sources this was the site of the cloister and structures belonging to the cathedral.

The excavation area was delimited to the east by a wall (US 11) belonging to the Palazzo dei Colonelli, to the west by the wall of the fortress’s bastion (US 25), and to the north-east by the remains of the supporting wall of a great brick-built vault that was also part of the Palazzo dei Colonelli.The stratigraphy in this point was disturbed in the modern period by the construction of a well covered by a slab of reinforced concrete (US 40).

Following the removal of the dense vegetation and humus, about 10 cm thick, three archaeological features, relating to occupation of the Genoese fortress between the 16th and 18th century, came to light. The first, constituted by a row of squared stone slabs bonded with mortar (US 02) situated exactly at the centre of the excavation area, was linked to the east to the second feature, formed by a patch of cobbled floor (US 03) in a mortar make up (US 46). The slabs forming US 02 were characterised not only by their regularity and large dimensions (90 × 40 cm) but also by the thickness, on average 15cm. The third feature, even more macroscopic, was an ample paving situated in the north-western sector of the excavation area, also formed by very large stone slabs. However, although the dimensions and thickness were similar, the layout was very different from US 02 given the irregularity both of the working of the slabs and their positioning. All three of the above stratigraphic units were on the same level, and thus it is possible to interpret them as contemporary and part of the same occupation level.

Both US 03 and US 16 presented clear traces of robbing, cut US -22 for the cobbles and US -26 for the paving. Presumably the paving slabs were removed in order to be reused. The earthy fill of both cuts contained pottery fragments of diverse dates which presumably came from outside of the site.
The removal of the fill from cut US -26, a compact layer of greyish-brown soil containing brick and stone fragments (US 15), revealed the floor’s construction. A mortar make up (US 17) emerged which overlay a substantial layer of broken brick/tile mixed with lime (US 14). Both layers can be interpreted as a specific intervention to reorganise the site and reconstitute a floor level.

The most important contribution to the identification of the remains of the earliest building, presumably late medieval, came with the removal of US 23. Characterised by an earthy layer similar to US 15 but darker in colour and situated between US 25 and 16, it was the fill of another cut (US -27) in US 16 itself. Its cleaning revealed a brick wall (US 30) on the same alignment as the perimeter wall of the fortress and separated from it by a cut (US -58), probably a drainage channel.

The removal of US 10, that is the fill of cut US -22, uncovered a further two dumps of material (US 45 and 48). This led to the identification of a second brick wall bonded with mortar (US 55) forming a 45° angle with the south edge of the excavation area, and which appeared to continue below US 02.

At the end of the campaign evidence of a least one structure preceding the occupation level constituted by US 02, 03 and 16 emerged. The removal of the stone slabs constituting US 02 and 16, and of the related make ups, together with the excavation of US 45 and 48, could therefore make it possible to go down to earlier levels belonging to the same occupation phase as walls US 30 and 55. It is hoped that, once uncovered, this phase will be prove to be coeval with the evidence already brought to light in previous campaigns in the cathedral and thus provided a more complete picture of the entire complex of Santa Maria Assunta.