<p>Building pathologies may result from structural deficiencies or unfavourable geotechnical conditions. When unstable ground affects diverse structures across wide areas, slow surface deformation often produces minor, unnoticed damage, commonly misattributed to poor construction in low-income districts. This study uses multitechnique Interferometric SAR (InSAR) to reveal large unstable sectors in Medellín, Colombia, disentangling structural from geomorphological drivers of damage hotspots. We integrated Sentinel-1 Small BAseline Subset&#xa0;(SBAS) and persistent scatterer interferometry (PSI) processing, automated active deformation area (ADA) extraction, detailed geomorphological interpretation, and city-wide structural damage reports from the municipal risk management agency. Multiple ADAs with line-of-sight velocities exceeding −70&#xa0;mm/yr were identified, focusing on three sectors (“Doce de Octubre”, “Manrique”, and “Villa Hermosa”). InSAR-detected deformation coincided with gravitational landforms, suggesting reactivation of large, slow-moving deep-seated mass movements and a previously unrecognized deep-seated gravitational slope deformation system in the Aburrá Valley hillslopes. Statistical analyses showed no relationship between building type and ground motion, but strong spatial clustering and overlap between ADAs and neighbourhood-level damage densities, especially in the northeast. Recent 2025 landslides occurred within preidentified zones, validating the instability mapping. A detailed geomorphological assessment based on high-resolution digital elevation models and historical aerial photographs supports the hypothesis that extensive sectors of the city are affected by slow-moving, deep-seated landslides. This finding challenges the prevailing assumption that building damage hotspots in Medellín are primarily caused by construction deficiencies and underscores the need to incorporate slow-moving landslide processes into urban hazard management strategies.</p>