Etruscan harbours in Tyrrhenian Italy were rarely searched and found, even though much evidence prevails, from ancient texts to artefacts. They were commercial hubs on an Etruscan and even Mediterranean scale. Bronze and iron objects, food products, and wine constituted the major part of exchanges. Some hypotheses explain this archaeological hiatus by the fact that Etruscans use their natural environment and calm places for the establishment of harbour basins. These environments were dominated by bedrocks and lagoons during Antiquity and remain poorly understood, in particular their diachronic evolution. The Populonia and Talamone cases show this. They have mainly been studied for their necropolis, acropolis, and temples. A comprehensive geoarchaeological study could close the gap between harbours and their surrounding environment. This study drafts this pluridisciplinary consideration by a bibliographic synthesis based on existing data (historical, archaeological, geological, geomorphological, palaeoenvironmental) and a multi-proxy analysis (sediments, ostracods, shells, minerals) on the two first sedimentary cores from Fonteblanda, in the gulf of Talamone. Cores couldn’t confirm nor invalidate the existence of a harbour but could offer data about the environment evolution since the beginning of the Holocene. They illustrate the part of the watershed and the sea in the gulf of Talamone’s context. By combining these studies, it is possible to propose a hypothesis on the location of harbours in Etruscan times and to formulate the coming fieldworks (geophysical, terrestrial, and underwater surveys, archaeological excavation, sedimentary cores).