Altxerri (Aia, Gipuzkoa)

Altxerri cave is located in the municipality of Aia, less than a kilometre from the border with the municipality of Orio, on the left bank of a tributary of the Oria estuary (Altxerriko Erreka). Its mouth opens on the eastern slope of Mount Beobategaña, just a few metres from the Altxerri farmhouse, from which it takes its name. The system, which is 2.5 kilometres long, runs along a narrow band of Cretaceous limestone; loamy and micritic, of Maastrichtian – Danian age.

Between 2020 and 2021, the Altxerri cave was the subject of a study for the protection of Palaeolithic rock art, together with those of Santimamiñe and Lumentxa (Bizkaia). This project, called “Kobabes: kobazuloen dinamika eta labar artearen babesa” (021-KOI-2020), was financed by the Department of Culture and Linguistic Policy of the Basque Government – Eusko Jaurlaritza, and approved by the Cultural Heritage / Ondarea services of the Provincial Councils of Gipuzkoa and Bizkaia.

Through this project we have been able to confirm the archaeological and geomorphological potential of this cave in the municipality of Aia. In the opinion of our research team, it would be advisable to carry out an exhaustive survey of the floor and walls inside the cave, in order to discover, mark and protect the elements of the internal archaeological context that make up the cave. In this new project, directed by Dr. Mª Ángeles Medina-Alcaide, at least one micro-survey is proposed to discover the original stratigraphy of the cave.

These remains, in turn, would shed light on the true potential of this cave, which was discovered more than 50 years ago. As previously indicated, their study could tell us when prehistoric societies entered the cave (e.g. radiometric dating of coals and bones); what the anthropised karst setting was like or how they progressed inside (e.g. geomorphological and accessibility study); what fuel was used for illumination and what duration and intensity it provided (e.g. anthracological study of the anthropogenic fuels used in the cave). e.g. anthracological study of coals and analysis of rubefacted areas); what was the sex, age or pathologies of the people who created the works of art (anthropological study of human remains, human footprints and handwriting); what materials they carried and what use they made of them in the interior areas of the caves (e.g. traceological study of lithic pieces), etc. In this way, we can reconstruct the material and human efforts devoted by Palaeolithic societies to symbolic activity inside the caves.

In addition, we have proposed to update the 3D dimensional topography carried out ten years ago, allowing us to geolocate all the elements of historical interest located in the caves (both parietal art and other archaeological elements that we can locate and document). Knowing their exact location allows us to know data that will guarantee their protection (e.g. the exact distance between the exterior and the archaeological element, etc.). On the other hand, by carrying out a 3D renovation of the Atxerri cave, and based on the data obtained from the various archaeological and geomorphological studies carried out in the cave, we can virtually reconstruct it to obtain a replica of what this World Heritage Site looked like in the Palaeolithic, when it was walked and decorated (e.g. by locating the original open entrances, reconstructing the altered passages, recreating the lighting used in the Palaeolithic to illuminate it, etc.).