Investigations in the hamlet of Trebbio began in 1990, when a series of surface surveys began which revealed pottery, metal objects and faunal remains datable to between the end of the 9th and the 7th century B.C.

In 2002 excavations began and the first campaign brought to light the remains of a production area characterized by several structures including 3 well preserved semi-interred kilns, two of which were for pottery production. Both were of the same typology with praefurnio and round combustion chamber with plastered walls. Several pits were found which probably relate to the activities undertaken around the kilns.

On the western side of the excavation an inhumation with two skeletons was found; it contained no grave goods. The terminus post quem indicated by the Roman materials in the fill, the grave typology and radiometric tests place the burial in the early medieval period. In 2004 a second burial was found. This was similar to the first in orientation and the absence of grave goods but contained a single deposition and constitutes evidence for the presence of a necropolis in the area. The probable existence of a 6th-8th century B.C. necropolis at Trebbio is of particular importance, given the vicinity of this locality to the historic centre of Sansepolcro

In 2004 and 2005 numerous pits used for domestic rubbish or connected to craft working activities and post holes were found. The recovery of a large quantity of pottery in 2006 documents the settlement’s trading contacts with areas such as the Padovan Plain, Umbria, Latium and the Piceno area between the 9th and 6th century B.C. (a period indicated by the presence of a footed cup with two handles).