Abstract Beachrock formation developed at two different localities at the coasts of Gelibolu Peninsula. Geomorphological, geological, and tectonic properties of the coastal area have been considered in this study. All beachrock localities have been investigated in detail considering their material types, sequences, structures and depositional localities. It was concluded that the beachrocks observed in a distance of 8 to 15 meters from the present shoreline were found under the present sea and they have been tectonically uplifted. Sea level changes and tectonic activity of the coastal area have been explained owing to the properties of these young formations.