In contemporary discourse, there is a systematic endeavor to repurpose decommissioned military installations, aligning them with the principles of sustainable development and the promotion of social cohesion. Simultaneously, efforts are being made to harness these spaces as cultural resources. The cultural advancement of urban environments, through the elevation of local historical narratives, functions as a pivotal strategic planning mechanism contributing to endogenous sustainable development and bolstering sustainable tourism. The core objective of this study is to examine the adaptive reuse of the inactive military structures of the Southern Naval Fortress in Perdika, Aegina, Greece, with the aim of transforming them into a historical and cultural park integrated with a multifaceted cultural route. A methodology based on a comprehensive literature review, combined with a case study design, was employed to inform the strategic planning process, emphasizing the development of specific actions for the Fortress. This involved a detailed mapping of the facilities and surrounding areas as integral elements of Aegina's cultural capital, alongside the formulation of a development vision, strategic planning for the reuse of the Aegina Fortress, and recommendations that could establish the prerequisites for holistic endogenous growth. Furthermore, the study addresses the potential implications for key stakeholders and policymakers.