In 2017 two archaeological trenches of 5 x 5 m were explored in the marine bay at the mouth of the Ropotamo River (fig. 1). Rich materials from Antiquity, Late Antiquity, Middle Ages and the Ottoman period were discovered. Stratigraphic position and nature suggest that the finds form an accumulation from a harbor that operated at this place in the historical periods (fig. 2). At a depth of 2.5 m in the ground are found prehistoric ceramic fragment of handmade pottery, wooden post of a building structure and remains of a hearth (fig. 3). Although explored on a small area, these finds can be identified as remnants of the sea submerged EBA prehistoric site. The ceramics of the settlement date back to the I–II phase of the EBA. The 14C sample from the above mentioned wooden post (SUERC-77016 is 4474±21 BP), gives after calibration a date between 3335–3031 calBC, which correlates with cultural attribution of the site.