The Mahndorf district of Bremen is located at the end of the Bremen dune and has been in the focus of archeology since the 1930s due to the large migration-period to early medieval burial ground. Since then, repeatedly various settlement sites from the first millennium AD have been discovered and partially excavated. The NIhK is currently researching the palaeolandscape of the Mahndorfer Marsh in cooperation with the Bremen State Archeology. In the Mahndorfer Marsh various fossil watercourses have been identified with settlements from the Roman Iron Age laying on their banks. Was the proximity to the rivers deliberately chosen by the settlers in order to use them as important transport routes? The terrain relief and the fossil river courses are reconstructed diachronically with large-area geomagnetic measurements, coring transects and laboratory analyzes, thus providing a detailed insight into the living conditions and the settlement structure.