Nazar Research Center for Art, Architecture and Urbanism (NRC) The Monthly Scientific Journal of Bagh-e Nazar 1735-9635 23 156 (Specified Issue of International Conference on “Architectural Heritage at Risk,”) 2026 05 22 Mountain Fortresses of Northwestern Iran: A Study on the Risks to Defensive Architectural Heritage Mountain Fortresses of Northwestern Iran: A Study on the Risks to Defensive Architectural Heritage 79 96 243908 10.22034/bagh.2026.571175.5976 FA Mehdi Kazempour Faculty of Cultural Materials Conservation, Tabriz Islamic Art University, Tabriz, Iran Journal Article 2026 01 06 <strong>Problem statement: </strong>In Iran, fortresses are generally classified into two categories: mountain fortresses and plain fortresses. Mountain fortresses were constructed along mountain passes, on ridgelines, beside valleys, or near rivers, primarily with the purpose of providing security and defense. In northwestern Iran, due to its distinctive topographical features, thousands of mountain fortresses exist. These structures have been built from the fourth millennium BCE coinciding with the emergence of political and social instability and their construction continued until the Qajar period. The architectural plans of these fortresses were strongly influenced by the topographical characteristics of their surrounding landscapes, and local stone materials were predominantly used in their construction. Owing to their mountainous geographical setting and the use of indigenous materials, these fortresses are highly vulnerable to various forms of deterioration. The research addresses two main questions: What materials were most commonly used in the construction of mountain fortresses? And which factors have had the greatest impact on their deterioration? <br><strong>Research method:</strong> This article, employing a descriptive-analytical method and relying on both fieldwork and library-based studies, examines the natural and human factors contributing to the destruction of these monuments, including precipitation, frost action, soil erosion, and anthropogenic impacts. <br><strong>Conclusion:</strong> The findings indicate that the primary construction materials of mountain fortresses in northwestern Iran are stone and sarooj mortar, while factors such as erosion, earthquakes, human intervention, and environmental conditions have had the most significant impact on their destruction. <strong>Problem statement: </strong>In Iran, fortresses are generally classified into two categories: mountain fortresses and plain fortresses. Mountain fortresses were constructed along mountain passes, on ridgelines, beside valleys, or near rivers, primarily with the purpose of providing security and defense. In northwestern Iran, due to its distinctive topographical features, thousands of mountain fortresses exist. These structures have been built from the fourth millennium BCE coinciding with the emergence of political and social instability and their construction continued until the Qajar period. The architectural plans of these fortresses were strongly influenced by the topographical characteristics of their surrounding landscapes, and local stone materials were predominantly used in their construction. Owing to their mountainous geographical setting and the use of indigenous materials, these fortresses are highly vulnerable to various forms of deterioration. The research addresses two main questions: What materials were most commonly used in the construction of mountain fortresses? And which factors have had the greatest impact on their deterioration? <br><strong>Research method:</strong> This article, employing a descriptive-analytical method and relying on both fieldwork and library-based studies, examines the natural and human factors contributing to the destruction of these monuments, including precipitation, frost action, soil erosion, and anthropogenic impacts. <br><strong>Conclusion:</strong> The findings indicate that the primary construction materials of mountain fortresses in northwestern Iran are stone and sarooj mortar, while factors such as erosion, earthquakes, human intervention, and environmental conditions have had the most significant impact on their destruction. https://www.bagh-sj.com/article_243908_35d942d4786cf125e4f77f45425ccd2d.pdf