This research aims to explore and introduce selected international experiences in the multi-purpose utilization of urban subsurface spaces as shelters or secure areas with alternative functions, and to derive operational strategies applicable to Tehran. Framed as an applied study, the research adopts a review-based approach to analyze global precedents, with the goal of developing a structured model for their contextual adaptation in Iran. Case studies from the United Kingdom, Russia, Ukraine, and Israel were examined, chosen both for the availability of essential data and for their relative similarity to Tehran’s current urban and security conditions. Findings highlight that metro stations, due to their centrality in citizens’ daily routines and their associated sense of familiarity and psychological attachment, have historically been the most widely utilized civilian shelters during wars and bombardments. Despite Tehran’s extensive infrastructure—comprising approximately 160 metro stations, multi-story parking structures, underground commercial complexes, and tunnels—the city has so far lacked a clear framework for the multi-purpose use of these spaces in wartime, primarily due to the long absence of direct hard-security threats. However, in the aftermath of the significant experience of the 12-day imposed war led jointly by Israel and the United States against Iran, an urgent need has emerged to adopt an operational and intelligent approach for preparing these spaces to serve as civilian shelters in the event of future attacks. The study concludes by proposing a seven-stage process for transforming Tehran’s metro stations into functional shelters, offering a practical roadmap for enhancing urban resilience and crisis preparedness.