Public access to underwater and maritime cultural heritage has proven to have a very positive effect on the local economy. This type of heritage is very attractive for the cultural tourism sector in general and for active and diving tourism. The Nautical and Underwater Archeology Line of the University of Cadiz, within the framework of the TIDE Project (Interreg Atlantic Area) and Herakles Project (FEDER-UCA18-107327) have been working on the enhancement of maritime and underwater heritage through the application of new technologies. In this paper, we will present the advances in the project in the Strait of Gibraltar, based on the first phase of scientific analysis and on the definition of a common working methodology that has resulted in a toolkit for the development of tourism activities linked to the MCH and UCH. Pilot activities under development are focused on accessible underwater heritage routes, VR applications to create Dry Dive experiences and the streaming of underwater archaeological works, thanks to a bottom-surface acoustic communication buoy. Results show that these types of outreach solutions and, by extension, of tourism application, must be preceded by a rigorous archaeological research process, a study of the target audience and the evaluation of the carrying capacity of the sites, to avoid falling into the mercantilisation or deterioration of the UCH. On the other hand, virtual or indirect access solutions are very useful, but always through the correct interpretation of the heritage.

Over the last few years, due to various climatic, anthropogenic, and environmental factors, a large amount of submerged heritage has been unearthed and exposed to deterioration processes in the Bay of Algeciras. These impacts can be more severe in shallow waters, where the cultural heritage is more vulnerable to natural and human-induced impacts. This makes it urgent to document cultural heritage at risk of disappearing using different techniques whose efficiencies in the archaeological record need to be determined and compared. For this purpose, we have documented a shipwreck in the Bay of Algeciras using two techniques: photogrammetry and a multibeam echosounder. The photogrammetric method consists of obtaining a 3D model from numerous photographs taken of an object or a site. The processing software creates three-dimensional points from two-dimensional points found in the photographs that are equivalent to each other. Multibeam echosounders are capable of providing side scan imagery information in addition to generating contour maps and 3D perspectives of the surveyed area and can be installed in an unmanned surface vehicle. As a result, we have obtained two 3D visualisations of the shipwreck, i.e., digital copies, that are being used both for the analysis of its naval architecture and for its dissemination. Through the comparison of the two techniques, we have concluded that while a multibeam echosounder provides a detailed digital terrain model of the seabed, photogrammetry performed by divers gives the highest resolution data on objects and structures. In conclusion, our results demonstrate the benefits of this combined approach for accurately documenting and monitoring shipwrecks in shallow waters, providing valuable information for conservation and management efforts.

Here, we sought to reconstruct the Pleistocene and Holocene evolution of Cartagena Bay. Therefore, 16 borehole cores were analysed with the following aims: (1) to define a chronological framework; (2) to obtain data on the palaeoenvironment; and (3) to establish the relationship with human activities, especially focused on the reconstruction of the Carthago Nova (also known as Qart Hadasht) conquest. A total of 147 samples were recovered for amino acid racemisation (AAR) dating; 32 for radiocarbon dating (¹⁴C); and 159 for sedimentological, palaeontological, and biomarker determination. These approaches allowed us to elucidate the evolutionary phases of the palaeolandscape in Cartagena. The simultaneous use of AAR and ¹⁴C dating allowed the discrimination of spurious ages and the establishment of a chronological scale. During the Marine Isotope Stages (MIS) 7 and 5, the sea level (SL) in Cartagena Bay was almost the same as today. An alluvial plain developed in the northern area, and a delta was formed by an ephemeral river. In contrast, during MIS4, after a fall in SL, a wide sandy coastal plain emerged, leading to the accumulation of colluvial and aeolian deposits. The Holocene transgression was reflected in the hinterland in a late and temporarily floodable marsh fed by alluvial fans and creeks, producing a salinity gradient from freshwater to brackish and saline waters. Along the sea front, the marine influence was evident but not dominant, grading up and landwards to saline and freshwater marshes. Therefore, at the time of Scipio’s conquest, the geography of Carthago Nova was quite different from that described by Polybius. The Roman’s sudden attack seized Qart Hadasht from the south-west, avoiding the marshy area and not crossing a fast and deep ebb stream as it never existed on the Mediterranean Iberian coast.

The city of Cartagena and its immediate surroundings have experienced significant topographical changes throughout its history. Originally built on five hills which border south and west with the Mediterranean Sea, the city has expanded to the north over the last five decades, occupying a lacustrine system which has now dried up due to the diversion of riverbeds which, from time to time, used to flood the place. These changes have been documented and studied from the lithology present in over 400 geotechnical drillings carried out in the urban renewal of the city for the last two decades. In addition, another 20 new continuous drillings have been conducted within the Project “Surveying and planning a privileged Mediterranean city, Arqueotopos I and II” which is still ongoing. The information obtained is completed with the study of all existing historical maps on it. Digital Terrain Models (DTMs) have been generated with this drilling data, then several lithological layers have been selected for its interest: anthropic fill, mud and underlying bedrock. The thickness of each of the layers has been studied in different areas and viewed through various longitudinal profiles that have been plotted. Finally, a three-dimensional (3D) virtual reconstruction has been undertaken to see graphically the documented changes that have occurred in each of these layers, to serve both research and divulgation knowledge.