The Beyglarbeygi mansion and takyeh, one of the prominent architectural monuments of the Qajar era located in the Feyzabad neighborhood of Kermanshah, requires a comprehensive seismic performance assessment due to its location in a high-seismic-hazard zone. This study evaluates the seismic performance of the Beyglarbeygi mansion and takyeh, as masonry structures, under the design earthquake using nonlinear dynamic analysis and identifies critical structural zones based on performance indicators. To this end, a three-dimensional finite element model of the structure was developed in Abaqus, and nonlinear time-history analyses were performed. The numerical model was validated by comparing the structure's natural frequencies with available in-situ assessment data, demonstrating satisfactory agreement. The results indicate that the structure is particularly sensitive and vulnerable to design seismic loads along its western and northern facades, where a maximum displacement of 104.3 mm was recorded. The novelty of this research lies in correlating the analytical damages observed after the Ezgele earthquake of November 21, 2017, at an azimuthal distance of 130 km, and in presenting a performance-based assessment using multiple simultaneous indicators, including stress, strain, and displacement, for a historic masonry structure subjected to the design earthquake. Critical structural zones requiring localized seismic retrofitting interventions were successfully identified.