The Grotta di San Biagio is situated a few kilometres from Ostuni (292 m a.s.l.), close to the sanctuary of San Biagio from which it takes its name. This is a large karstic cave, rich in stalactite and stalagmite formations, at present linked to the exterior via a short cuniculus, artificially widened following the grotto’s discovery in the 1950s. Excavations have documented occupation of the cave between the end of the Neolithic and early phases of the Eneolithic periods, when the entrance to the cave must have been similar to the present situation - that is difficult to access which suggests that the cave was not used as a dwelling. Therefore, it is possible that the cave was used mainly for cult and funerary purposes, as attested by the presence of decontextualised human remains. On this basis it is probable that the identified features relate to cult structures in which simple rites were practiced involving lighting of fires and food consumption. During the 2010 campaign the trenches were extended across almost the entire rear area of the cave, becoming a single area open excavation. Two large structured hearths were identified, probably relating to different periods of use, one at the centre of the cave and the other on the north-eastern side, on top of a deposit of red earth. The structures were sub-circular characterised by the presence of grey ash interspersed with charcoal layers and surrounded by stones. The hearth on top of the red earth deposit (diameter about 80 cm) was built of a series of flat stones laid on edge and arranged around it; it was filled with greyish ash. Outside the hearth, large rocks were found on the eastern side of the cave, perhaps deliberately placed to form some sort of structure. Furthermore, the investigations identified a large enclosure on the western side, perhaps delimiting the northern part of the cave, along its perimeter. The structure comprised large blocks arranged horizontally in irregular courses, probably bonded with compact red earth. Inside the enclosure the archaeological deposit was characterised by levels of gravel interspersed with charcoally or blackish-grey lenses, containing numerous pottery fragments, some reconstructable, animal bone and objects of personal ornament. Inside the enclosure a circular pit of a ritual nature was identified, bordered by small and medium- sized stones, with a diameter of circa 50 cm and depth of 60 cm. The walls were partially reinforced by larger stones and the fill was loose. Diverse elements were found inside the pit suggesting its cult function. Together with numerous large animal bones, there was a double point on a worked bone of circa 15 cm in length, a bivalve shell filled with yellow and red ochre, a grey flint scraper point probably from the Gargano, a large jar fragment painted in the Serra d’Alto style with meander and cruciform motifs, and at the base of the well a bone figurine, probably female with a bird mask, which can be ascribed to the tradition of Neolithic anthropomorphic and zoomorphic figurines of the Serra d’Alto _facies_.

This campaign continued work on the grotto floor. Inside an enclosure of large collapsed blocks, arranged so as to contain the red earth, at least two new sub-circular hearths about 1 m in diameter were identified (US 237 in J15, I15, US 239 in J124, J15), together with faunal remains. The hearths were not structured but consisted of small, reddened stones, probably representing two fires used over a short period of time, with respect to the two large hearths present in the same area (US 231, US 212). However, there was an abundance of charcoal and ash in some areas adjacent to the hearths, covering up to 2 m2 (US 238 in K16, L16, US 234 in K17, L17). Numerous vases were deposited around them. These containers were of Eneolithic type, decorated with grooves, applied bands in relief and handles with vertical grooves or lug handles. Relief cordon decoration below the rim and decorations formed by rows of finger impressions was also attested. A new excavation area was opened in front of the present entrance to the cave, denominated trench 2_cave entrance. The area covered 25 m2 (L35 – L31, P35 – P31) with a deeper section of 4 m2 in a niche constituted by large collapsed masses. This area was noticed during inspections undertaken in the 1970s, as the site of a probable combustion structure given the presence of a vast area (over 10 m2) showing ashy remains (US 1002 in L35, L32 e N35, N32). Following the removal of stones and clearing of the area, the excavation exposed a large structured circular hearth with a diameter of 1.20 m (US 1003 in M33, M32). It was slightly sunken and made up of medium sized stones laid in three courses. The interior contained faunal remains, pottery and abundant charcoal. The pottery was of the Eneolithic type already found inside the grotto. Based on the discoveries made in previous campaigns below several large collapsed boulders, it was decided to extend the new excavation area in order to investigate the archaeological deposit situated below, and partially covered by, a series of large rocks. Numerous fragments from painted vases of the Serra d’Alto type were recovered, one of which completely reconstructable. The discovery of these refined vessels documents the practice of depositing valuable vases and objects in the most restricted spaces within the grotto, a practice widespread during the Neolithic period, and which can probably be associated with groups of the Serra d’Alto Culture, as documented at other sites of this type.