This contribution discusses the potential of UAV-assisted (unmanned aerial vehicles) photogrammetry for the study and preservation of mining heritage sites using the example of Roman gold mining infrastructure in northwestern Spain. The study area represents the largest gold area in Roman times and comprises 7 mining elements of interest that characterize the most representative examples of such ancient works. UAV technology provides a non-invasive procedure valuable for the acquisition of digital information in remote, difficult to access areas or under the risk of destruction. The proposed approach is a cost-effective, robust and rapid method for image processing in remote areas were no traditional surveying technologies are available. It is based on a combination of data provided by aerial orthoimage and LiDAR (Light Detection and Ranging) to improve the accuracy of UAV derived data. The results provide high-resolution orthomosaic, DEMs and 3D textured models that aim for the documentation of ancient mining scenarios, providing high-resolution digital information that improves the identification, description and interpretation of mining elements such as the hydraulic infrastructure, the presence of open-cast mines which exemplifies the different exploitation methods, and settlements. However, beyond the scientific and technical information provided by the data, the 3D documentation of ancient mining scenarios is a powerful tool for an effective and wider public diffusion ensuring the visualization, preservation and awareness over the importance and conservation of world mining heritage sites.been also established as a standard of value and currency since the world's first coinage in Lydia (643-630 BC) [5]. However, significant advances in ore deposits prospection and exploitation did not occur until the onset of the New Age. The systematic exploitation of gold ore deposits may have started during the period of Roman domination in the Mediterranean. According to recent archaeological findings in the mining site of Pino del Oro (Zamora), Sánchez-Palencia et al. [6] suggest that the earliest prospection works in northwest Spain started during pre-roman times. The northwest Iberian Peninsula represents the largest Roman gold mining prospect in the world, with the Las Médulas world-class site as one of the most remarkable gold mines due to its important landscape transformation [7][8][9]. In this area, more than 93.5 billion m 3 of Cenozoic sediments were removed by the Romans, recovering upon 5 t of gold [10]. Due to its archaeological and natural values, this site was declared a UNESCO World Heritage Centre in 1997, although recent works based on Airborne Laser Scanning Technology (ALS) suggests that it may not be the largest Roman goldmining site in terms of recovered gold quantities [11,12].Roman gold mining works in northwest Spain were active from the 1st until the 3rd centuries AC. After that period, little gold mining-related information is known, with only minor documented exploitations during the Middle A...

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Villamayor Stone (VS) is an arkosic stone and is known by several names: (i) VS because the quarries are located in Villamayor de Armuña village (Salamanca, Spain); (ii) Golden Stone due to its patina, which gives the stone a ochreous/golden colour; (iii) Franca Stone is known locally and in historical documents. VS has several varieties ranging from channel to floodplain facies. In this work, we have selected three varieties. VS was quarried and used in the construction of Romanesque monuments such as the Old Cathedral, Gothic monuments including the New Cathedral and the University façade, and Baroque monuments, notably the Main Square. Also, VS was used in the reconstruction of the Roman Bridge (Salamanca, Spain). Currently, VS is quarried by a small number of family businesses, using traditional methods for cladding façades of new buildings. Unfortunately, part of the construction sector went bankrupt in the 2008 crisis. However, VS is still the main stone used in the city of Salamanca for the restoration of monuments, even though used in relatively small quantities in comparison with usage before the economic crisis. It is thus of great importance for future generations that their quarries and the craft of masonry be protected. This work proposes that VS should be designated as a Global Heritage Stone Resource.

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