The Etruscan town of Vetulonia (Castiglione della Pescaia, GR) has been the object of numerous archaeological investigations mainly undertaken between the second half of the 19th century and the early 20th century by Isidoro Falchi, doctor and amateur archaeologist. This research led to the discovery and excavation of part of the Hellenistic-Roman town and of large sections of the Villanovan and Orientalizing cemetery. The question that remains to be answered is the position of Vetulonia’s harbours and landing places on the ancient lake Prile. The wealth of the Etruscan town probably derived from the control of trade in raw materials from the Colline Metallifere, which reached the shores of lake Prile through the Bruna valley. Therefore, it is very probable that there were harbours or landing places on the lake shore close to the town, in places that were well-connected both to the town and the river Bruna. However, the uncertainty about the extension of the northern part of the lake and the obliterations resulting from modern land reclamation in the area, means that the positions of harbours or landing places serving Vetulonia on the northern shores of lake Prile are largely unknown.

Between 2016-2018 the Deutsches Archäologisches Institut Rom carried out four geophysical surveys in the localities of Uliveto, Basse agli Olmi, Badia Vecchia, Sestica and Poggetto, situated on the extremities of the Vetulonia hill, to the north-east of the present-day borgo. The surveys identified an area of great archaeological interest – already marked on the archaeological maps made by C. B. Curry – situated at the end of the via dei Sepolcri that leads to the borgo of Vetulonia. The images clearly show a U-shaped linear anomaly, c. 600 m long, with a rounded northern edge. The line encloses an area of c. 280 × 100 m inside which no anthropic anomalies were identified. Outside this structure there were numerous other anomalies of smaller dimensions, to be interpreted as the remains of masonry or brick-built structures with tile roofs.

In 2018, a campaign of core-sampling was undertaken in collaboration with the Freie Universität of Berlin. To the south of the large U-shaped structure, the cores documented the presence of layers relating to lake waters starting at a depth of 2.7 – 3.8 m from ground level. The sediments were between 40 cm thick in the core closest to the anthropic structures and at least 7 m thick in the core taken at 370 m south of them. The four cores taken inside the U-shaped structure contained neither anthropological materials nor lacustrine layers, rather the sediments were made up of a series of homogeneous compact sterile clays. The latter may be interpreted, at least in part, as colluvial/fluvial deposits from the surrounding hills. The C14 analysis on samples from three of the cores provided a date for the lacustrine and marine sediments between the early Holocene and the medieval period (c. 8399 – 300 cal BP for core VE5).