Digital Spatial Technologies to Compose the Map of the Southeast Iberia Megalithic Phenomenon. The Case Study of Fonelas (Granada, Spain)

Abstract

Megalithic landscapes in Southeast Iberia remain unevenly and insufficiently documented, particularly in rugged areas where traditional survey methods are limited. This paper addresses this gap by applying a multiscalar approach to the megalithic necropolises of the Fardes River (Granada, Spain), with the objective of detecting, documenting and interpreting poorly preserved prehistoric structures. To this end, an iterative workflow integrating remote-sensing techniques—specifically LiDAR-derived Digital Terrain Models (DTM) analysis and historical aerial imagery and RPAS photogrammetry—combined with systematic pedestrian surface survey was designed and tested. In the initial digital revision, 40 anomalies consistent in size (around 10–15 m in diameter) and morphology (circular) with known burial mounds of the area were identified. Field verification of these features confirmed 20 as positive archaeological features, comprising graves with tumuli and only orthostatic stone structures. Subsequently, RPAS photogrammetry was used on a selection of these verified sites to create high-resolution imagery and 3D models, allowing for detailed documentation and advanced interpretation. Additionally, a walled Chalcolithic settlement was recorded, characterized by concentric masonry alignments and associated material culture (e.g., hand mills, pottery and metallurgical tools). From a methodological perspective, this study evaluates the potential and limitations of remote sensing for detecting small-scale megalithic features (less than 20 m in diameter) often obscured by erosion, vegetation or subtle topographic expression. It demonstrates the value of an iterative survey model in which digital detection guides targeted fieldwork, and where field observations inform the subsequent application of advanced technologies such as RPAS for more precise documentation. This high verification rate (50%)—achieved through the complete ground-truthing of all detected anomalies—offers a replicable framework for surveying complex prehistoric landscapes and contributes new insights into the territorial organization and social complexity of Copper Age communities in Southeastern Iberia.