Trmun (north-eastern Italy): Multi-scale remote and ground-based sensing of a Bronze Age and post-Roman fortification

•Remote and ground-based sensing was applied to investigate an archaeological site.•3D identification of topographic archaeological anomalies and buried features.•An almost perfect match between remote sensing data and excavation evidence.•Discovery of a Bronze Age fortification and post-Roman towers.•Remote sensing is crucial to detect, monitor and manage cultural heritage. We have used multi-scale remote sensing to investigate a little known archaeological site in northern Istria (north-eastern Italy). Airborne Laser Scanning (ALS) and archaeological field surveys have allowed us to identify the position and extension of a large Protohistoric hillfort. Its highest and best-preserved sector, corresponding to a modest elevation at the eastern margin of the settlement, has been further investigated through thermal imaging, high-resolution ALS, drone Structure from Motion (SfM) photogrammetry and 3D Ground Penetrating Radar (GPR), leading to a detailed identification of unexpected buried features. An excavation campaign conducted in 2022 has confirmed the remote and ground-based sensing results. This excavation has led to the discovery of a Bronze Age fortification, partially reused and modified with the construction of 2 or 3 square towers during the post-Roman period. Our results demonstrate that the combined analysis of multi-scale remote and ground-based sensing is crucial to planning archaeological exploration in the field. Digital methods provide high-resolution topography and detect buried features that assist in monitoring and managing cultural heritage.