Despite the abundance of rock-cut architecture in Iran, comprehensive chronological and typological studies regarding this group of civilizational evidence have not yet been conducted, nor is there a map defining their spatial distribution. This research examines and analyzes five historical fortresses in Bijar County (Qamchogha, Qalāqourh, Dans-Qala, Dokhtar Zeynal, and Bashqurtaran), which represent prominent examples of hybrid defensive architecture (rock-cut and masonry) in the Central Zagros region. The primary objective of this study is to conduct a typology, chronology, and spatial analysis of these fortresses, emphasizing the factors influencing their formation, design, and spatial distribution. The central research question is: how have environmental (geological and climatic), defensive-security, and socio-political factors influenced the formation, typology, and spatial distribution of these rock-cut fortresses in Bijar? The research methodology is descriptive-analytical, utilizing a combination of library studies, field investigations (documentation via GPS and aerial photography), and interviews with local inhabitants. The findings reveal that these structures, primarily constructed during the Sassanid era and utilized throughout the medieval Islamic period, were shaped by the region’s geological characteristics (limestone and karst substrates) and geopolitical and defensive necessities. The results indicate that these fortresses, through the utilization of advanced systems such as rock-cut water cisterns lined with saruj (traditional hydraulic mortar) and strategic exit tunnels, demonstrate the high level of engineering knowledge possessed by their builders and reflect a sophisticated interaction between humans and nature in this climate. This study not only contributes to the chronology and typology of rock-cut architecture but also highlights the urgent need for the conservation and restoration of this civilizational heritage.