Determining precise boundaries and protective zones for historical and cultural objects enables their effective preservation. This article presents the framework for establishing protective zones around historical and cultural heritage sites existing in Ukraine, using the example of the Citadel defensive complex located in Lviv (Ukraine). It proposes general and detailed conceptual models for the combined application of remote and non-invasive methods for investigating historical and cultural heritage sites. It introduces the theory of integrating radar satellite imaging with ground-based georadar imaging. Additionally, it presents a software module that has been developed to analyze collected data on two-dimensional historical and cultural heritage objects, refine their boundaries, and establish protective zones around them. The result of the work is the determination of extremum points of vertical displacement on the territory of the historical and cultural heritage site “Lviv Citadel” in Ukraine using SAR, and the construction of a map of vertical displacements. A classification of these points was carried out, after which two of them were investigated using GPR for anomalies. Artifacts from World War II were discovered at each of these points. Using the developed software module, updated boundaries of the site were constructed, taking into account the underground artifacts and protective zones.