From Lost Trenches to Living Data: Using UAV-Mounted LiDAR to Relocate and Contextualize Legacy Excavations at Saqsaywaman, Cusco, Peru

LiDAR has transformed archaeological prospection by enabling the detection of sites and landscape features at unprecedented scales, particularly in environments with heavy vegetation. However, its methodological and analytical application at the excavation scale remains underdeveloped. In this paper, we develop a prospection‐oriented workflow that implements UAV‐mounted LiDAR to recontextualize legacy excavations within modern geospatial frameworks. We apply this approach at Saqsaywaman, the monumental Inka acropolis overlooking Cusco, Peru, a UNESCO World Heritage Site with nearly a century of intermittent excavation and uneven documentation. Our LiDAR survey covered approximately 69 ha, producing high‐density point clouds and derived terrain models capable of detecting subtle microtopographic signatures of past excavations obscured by vegetation and erosion. These LiDAR‐derived features were systematically compared with historic maps, archival aerial imagery, excavation reports and oral histories, and were verified through ground‐truthing. The analysis allowed us to relocate, with submeter spatial accuracy, over two dozen undocumented or poorly documented excavation trenches. Beyond preventing redundant excavation, this integration of LiDAR and archival data enabled the recontextualization of legacy stratigraphic data, radiocarbon dates and architectural descriptions alongside new excavations. At Saqsaywaman, the approach clarified preimperial occupation sequences in the Cruz Moqo sector and identified previously unrecognized architectural and hydraulic features. More broadly, the study demonstrates how LiDAR can function as a form of archaeological prospection focused on past research activity, extending the scope of prospection beyond site detection to the recovery and synthesis of legacy excavation data. Many major archaeological sites have been excavated repeatedly over decades, leaving behind fragmented records, imprecise maps and unpublished reports that complicate interpretation and risk redundant or destructive re‐excavation. Our workflow offers a replicable model for cumulative and sustainable archaeological research at sites worldwide.