Deliberate Closure of Constructed Spaces: An Anthropological Analysis of Backfilling and Sealing in the Ravne Tunnel System (Bosnia and Herzegovina) and Göbekli Tepe (Turkey)

Abstract

Subterranean tunnel systems across Europe and the Near East frequently exhibit evidence of post-construction modification, including blockage, infilling, and structural segmentation. In several cases, these features appear to reflect organized phases of closure rather than purely natural depositional processes. The Ravne tunnel complex in Visoko Valley (Bosnia and Herzegovina) provides a particularly well-documented example, with extensive field observations revealing repeated dry-stone wall constructions and stratified backfill deposits throughout the system.
Comparative analysis with underground sites in Cappadocia (Turkey), Ħal Saflieni (Malta), and Central Europe (Austria) indicates that intentional closure or controlled access restriction has been documented across multiple archaeological contexts, although it is expressed through different construction techniques and geological settings. At Ravne, the presence of 85 documented dry-stone walls, combined with sharply defined infill layers that contrast with the surrounding conglomerate matrix, is consistent with structured modification of subterranean passages.
Radiometric analyses from associated tunnel contexts provide additional chronological constraints, with radiocarbon and Uranium-Thorium dating of speleothem formations and organic materials indicating multiple phases of human activity and subsequent environmental stabilization spanning from the Neolithic to historical periods. These data do not directly date the initial excavation of the tunnels, but they establish a minimum temporal framework for the structural features and later modification processes.
Taken together, the stratigraphic, structural, and comparative evidence suggest that the Ravne tunnel system underwent systematic phases of modification, possibly including deliberate closure events. While alternative natural explanations cannot be entirely excluded in all cases, the recurring architectural patterns and contextual relationships observed across multiple sectors support the interpretation of organized human intervention.
This study contributes to broader discussions on subterranean architecture by highlighting the importance of closure phases as a potentially underrecognized component of underground system use, transformation, and long-term preservation.