Conservation challenges of the Iznik city walls: historical stratification and current practices

City walls have historically played a fundamental role in shaping the defense, identity, and spatial organization of urban settlements. The Iznik city walls, originally constructed during the Roman period and subsequently expanded in the Byzantine era, constitute a complex, multi-layered fortification system surrounding the historic city. This study examines whether current conservation practices adequately preserve the structural integrity and historical authenticity of these walls. Archival conservation records and survey drawings dated 1938 were analyzed alongside on-site assessments of recent restoration interventions. Through the combined use of historical documentation and field observations, the study reconstructs the original condition of the walls and critically evaluates contemporary conservation approaches. The findings reveal that current interventions are often fragmented and insufficiently aligned with internationally recognized conservation principles. In response, the study advocates a more integrated and methodologically grounded conservation approach that prioritizes the legibility of historical layers, authenticity, integrity, and comprehensive documentation in the preservation of multi-layered fortification systems.