Mycenaean tholos tombs are distinctive ancient monuments constructed as axisymmetric masonry structures (either dry or bound with weak mud mortar) that achieve self-stability through corbelled stone courses forming their vaulted roofs, later covered by earthen mounds. This study presents a simplified computational approach for geostructural analysis of these monuments to evaluate their structural integrity and inform restoration and protection efforts. The methodology involves two primary steps. First, a 3-D linear finite element analysis is conducted using area shell elements to model the tombs. The discrete nature of the masonry structure and material aging are incorporated by applying a Geological Strength Index (GSI) value, to provide adapted strength and deformation parameters at the microscale. Second, 2-D nonlinear soil-structure interaction staged analyses are performed on vertical and selected horizontal sections. Using the Hoek-Brown failure criterion for stone blocks and the Mohr-Coulomb criterion for the surrounding soil, dry joints, and mortar, these staged analyses interpret observed pathologies and assess response to normative loads. To address differences between 2-D plane strain conditions and the tomb's axisymmetric structure, corrective horizontal stresses derived from either analytical or numerical solutions or 3-D simplified linear analyses are applied to simulate the confining ring effect of the structure.