Throughout mankind's history, the need to secure and protect the home settlement was an essential one. This holds especially true for the city of Ainos (modern Enez) in Turkish Thrace. Due to its continuous settlement history since the 7th/6th century BC, several different types of city walls were built-sometimes even on top of each other-several of which have been preserved over time. To decipher the construction style, the course and the age of a buried city wall segment in the southern part of the former city, a geoscientific multi-proxy approach including magnetic gradiometer (MG) and electrical resistivity tomography (ERT) measurements in combination with granulometrical, sedimentological and microfaunistical investigations on sediment cores was applied. We were able to (1) present reasonable arguments for its Hellenistic age; (2) reveal the course of this wall segment and extrapolate it further north into a less studied area; and (3) demonstrate that in this near-coastal area, the former swampy terrain had been consolidated for constructing the wall. Our multi-proxy approach serves as a valuable example for investigating buried structures in archaeological contexts, avoiding a less-economical, time-consuming, or even forbidden excavation.They were primarily erected to provide security for the settlers and to give shelter in troubled times for the people living nearby. Additionally, they were an object of the city's representation, its power, and wealth. City gates, especially, were often decorated by rich ornaments to impress incoming guests. Fortifications counted among the biggest and most expensive building projects of communities. Due to their massive construction, ancient city walls, or at least parts of them, have survived at many sites until today. As important hints with regard to the historical and cultural evolution of civilizations, they are still the focus of current research [1][2][3][4].Chronology presents a huge problem when studying the history, construction, and utilisation of ancient city walls-especially of buried or partly ruined ones. Common dating methods are based on the investigation of their dimensions, especially width and course, gateways and towers, masonry style, as well as integrated pottery, inscriptions and spolia used [2].By applying a multi-proxy approach, this paper presents the results of a geoarchaeological, geophysical, microfaunal, and geochronological research on the buried part of the city wall in the south-western part of Ainos in order to (1) verify its construction style and age; (2) prove its further extension in less-studied and difficult-to-access areas; and (3) decipher the general landscape evolution in this part of the city during the past 5000 years. This approach has been widely adopted in Mediterranean coastal studies e.g., [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] to investigate lateral and vertical changes in the sediment stratigraphy and to probe the evolution of the landscape, notably coastline migration. Furthermore, Elaia [22],...