## 2 Location, Natural Environment, and Geology  
The Benzu rock shelter and caveare located in the western sector of the territory of the autonomous city of Ceuta (Spain), on the Strait of Gibraltar's African shore, at an altitude of 63 m.a.s.l. and about 200 m from the current coastline (Figure 1a).  
Figure 1: (**a**) Geographical location map, (**b**) Gibraltar arc geological map, indicating stratigraphic continuity between both sides of the Strait of Gibraltar and (**c**) geological map of the area de Benzu,  
with fracture lines in the Triassic carbonate materials of the cove and cave (adapted from Mapa Geologico Nacional MAGNA, IGME). Geologic key: Permo-Triassic phyllites and schists (6); Triassic quartzites and phyllites (7); Triassic colomites (8); Palaeozoic schists and conglomerates (10); Devonian limestones and sales (12); Cenozoic-Oligocene sandstones and siltstones (17); Quaternary detritic sediments (20, 22, 23). The location of the cave and rock shelter is marked with a yellow star.  
The Benz\(\acute{\text{a}}\) rock shelter [21; 22] is characterised by a precipitous topography (Figure 2), with almost vertical slopes, open in Triassic dolomitic rocks. Currently, most of the ceiling has collapsed, and the fallen blocks can be seen scattered on the slope that leads to the site. Before the new digital model was generated, its known dimensions were 15 \(\times\) 4.50 m.  
The Benz\(\acute{\text{a}}\) cave [26] is located just a couple of metres to the southwest of the Benz\(\acute{\text{a}}\) rock shelter, and presents a narrow and steep entrance which is 5.4 m long and 4.6 m wide (total pre-model area: 14 m\({}^{2}\)) [32].  
From a geological point of view, the site de Benz\(\acute{\text{a}}\) and the region around Ceuta is in the confluence between the Rif and Baetic mountain ranges, in the Albor\(\acute{\text{a}}\)n domain (Figure 1b) [33; 34]. These materials correspond to the Mesozoic-Cenozoic paleomargins of the Iberian and African Plates, respectively. Structurally, the Flyshs units and the pre-dorsal units are situated between the Albor\(\acute{\text{a}}\)n domain and the Sub-Iberian and Maghrebi domains [34; 35]. In the south of the external Rif Zone, non- or post-orogenic foreland tertiary basins are found: their geology is equivalent to that of the Guadalquivir Valley in the external Baetic zone [34] (Figure 1b). Regionally, different complexes can be found in the Ceuta region, such as the Alpuj\(\acute{\text{a}}\)rride/Seb\(\acute{\text{i}}\)to complex, the Malaguide/Gomaride complex, and the pre-dorsal Rif units, comprising limestone units mainly from the Triassic and Lower Jurassic. The karst-formed materials in the Yebel Musa formation are very similar to those in the Rock of Gibraltar, and this reflects on the Triassic dolomitic rocks of the Benz\(\acute{\text{a}}\) rock shelter and cave (Figure 1c), on the Lower Jurassic limestones of the Lower Jurassic Ridge, and on the Lower Jurassic dolomites of Yebel Musa (Figure 1b) [36]. Other rocky outcrops found near the cave and shelter are blue-grey phyllites, quartzites, Permo-Triassic schists, limestones, and red marks and pelites, with alternating Flysch sandstones [37; 38; 39]. Finally, anthropic alterations undergone by the cave since the earliest human occupation must have been minimal compared to exogenous processes, including cementation in limestone breccias, which has contributed to the preservation of archaeological artefacts. It is also possible that the front ceiling of the shelter collapsed during the Quaternary as a result of external geological processes [25], and due to the influence of coastal erosion processes in recent geological periods.  
Figure 2: (**A**) Historical photograph (first half of the 20 th century) of the Mogote de Benz\(\acute{\text{a}}\) with the quarry and fort de Benz\(\acute{\text{a}}\) and (**B**) photography dated to 2010, illustrating the advance of the quarry, and the disappearance of the fort.