Abstract: The Lalmai-Mainamati region in Cumilla, Bangladesh, designated as a UNESCO Tentative World Heritage Site, is historically associated with the ancient Buddhist civilisation of Samatata. This study aims to comprehend the cultural significance of Buddhism in the region through a comprehensive Geographic Information System (GIS)-based database of archaeological sites, featuring a structured data table with geographic coordinates and additional information, complemented by scaled digital maps. Notwithstanding its historical importance, documentation is insufficient, with about 23 sites officially recorded by the Department of Archaeology, Bangladesh. Nevertheless, significantly more than 55 sites have been recognised in literature and surveys. Numerous sites remain unexcavated, and current maps differ in both scope and precision. A mixed-methods approach was utilised, integrating GIS, Remote Sensing, literature studies, and ground-truthing. Research indicates that 77% of locations remain unexcavated. The dense aggregation of Buddhist edifices on the eastern inclines indicates a deliberate positioning for both spiritual and defensive purposes. This is the inaugural endeavour to comprehensively document the region digitally.