The location of landmark buildings in Iran’s historic cities during the Qajar period was shaped not merely by site selection or functional requirements, but by interactions among power structures, economic relations, social organization, accessibility networks, and geographical characteristics. This study aims to explain the logic underlying landmark building locations and examine their relationship with the spatial structure of six cities: Tehran, Tabriz, Isfahan, Kashan, Yazd, and Kerman. Using a historical-comparative approach, the research analyzes relationships between landmark buildings and urban structures across five dimensions: social, economic, political, geographical, and network-related. Data were collected from historical documents and maps, visual sources, morphological studies, and research on architecture and urban history. The findings identify four major patterns of landmark building location: market-oriented, power-oriented, neighborhood-oriented, and geography- and water-oriented. These patterns interacted to shape each city’s spatial structure. In Tehran, political power concentration and government interventions played prominent roles, whereas in Tabriz, the city’s status as the crown prince’s seat and integration into transregional trade networks were significant. In Isfahan, the inherited Safavid spatial structure intersected with the political, religious, and economic relations of the Qajar era. In Kashan, the bazaar and commercial capital played central roles. In Yazd, water resources, qanat networks, and neighborhood organization influenced building locations, while in Kerman, the relationship between the bazaar, endowed complexes, and regional economy was decisive. Overall, landmark locations were integral to buildings’ functions, status, and historical significance.