Abstract
<jats:p>This study investigates selected remains of modern defensive structures located in the Biała Nida basin (Poland), focusing on factors that have shaped their current condition. The analysed features include several sections of an anti tank ditch attributed to the German Reich, constructed as part of the A-1 defensive line against the Red Army in the final stage of World War II. Within a relatively small area, these structures were built on highly variable substrates, including fluvial sands and gravels, limestone rubble, and bedrock. Using an integrated approach that combines historical cartographic data, Airborne Laser Scanning (ALS) analyses, field observations and measurements, geomorphological assessments, historical sources, including military instructions, and GIS-based spatial analysis, the main degradation and transformation factors were identified. Natural components, including fluvial dynamics, slope processes, and soil erosion, are evaluated alongside anthropogenic impacts including land use change, infrastructure development, and agricultural intensification. The results highlight the varying vulnerability of individual sites and demonstrate how the synergy of natural and human-induced processes contributes to differential preservation patterns, thereby enabling the identification and dating of other remains of modern defensive structures.</jats:p>