A prehistoric Pyrenees cave may have been an early copper-processing camp repeatedly used for thousands of years, with archaeologists also uncovering child remains and symbolic jewelry.
Archaeologists working high in the eastern Pyrenees have uncovered evidence that a prehistoric cave may have been used for early copper processing. The site contains numerous hearths filled with fragments of green stone, and researchers believe the cave was visited repeatedly over a span of 2,000 years.
The findings challenge earlier ideas that prehistoric people only spent brief periods in high-altitude environments. The discovery of a child’s finger bone and baby tooth also raises the possibility that the cave may have served as a burial site.
“For a long time, high-mountain environments were seen as marginal, places prehistoric communities passed through occasionally,” said Prof. Carlos Tornero of the Catalan Institute of Human Paleoecology and Social Evolution, lead author of the article in Frontiers in Environmental Archaeology.
“But we found a really rich archaeological sequence, including multiple combustion structures and a very large number of green mineral fragments. We can’t say exactly how long people stayed each time, but the repeated use of the space and the density of remains suggest occupations that were short to medium in duration, but happening again and again over long periods of time.”
Ancient Hearths and Malachite Hint at Early Copper Processing
Cave 338 sits at an elevation of 2,235 meters (7,333 feet) in the Freser Valley. Researchers excavated a 6 square meter (65 square foot) area near the entrance and identified four occupation layers. The newest layer was relatively thin and included artifacts from historical periods, suggesting limited use during that time. The oldest layer, dating back about 6,000 years, contained only charcoal remains.
The most significant discoveries came from the second and third layers, where archaeologists uncovered 23 hearths containing crushed and burned green mineral fragments. Detailed testing is still underway, but the material resembles malachite, a mineral associated with copper production. If confirmed, the cave may represent an unexpectedly early high-altitude mining and processing site.
“Many of these fragments are thermally altered, while other materials in the cave are not, which clearly suggests that fire played an important role in their processing and that there was a deliberate intention behind it,” said Dr. Julia Montes-Landa of the University of Granada, co-author. “In other words, they weren’t burned by accident.”
The overlapping hearths show that people returned to the cave many times over long intervals. Radiocarbon dating indicates the hearths in the second layer are about 3,000 years old, while those in the third layer date from roughly 5,500 to 4,000 years ago.
Child Remains and Rare Jewelry Reveal Ritual Possibilities
Researchers also uncovered human remains in the third layer, including a finger bone and a baby tooth from at least one child around 11 years old. The findings may indicate the presence of deeper burials within the cave. However, scientists cannot yet determine the cause of death or confirm whether both remains belonged to the same child.
“We recovered two pendants: one made from a shell and another from a brown bear tooth,” said Tornero. “They come from prehistoric contexts, most likely around the second millennium BC. The shell pendant is interesting because it has parallels in other sites in Catalonia, which suggests shared traditions or connections between different communities. The bear tooth pendant is much less common. That might point to something more specific or symbolic, possibly linked to the local environment.”
Although Cave 338 was not a permanent settlement, the repeated visits suggest the location held long-term importance. Researchers hope future excavations will reveal more about how people used the cave and where the green mineral originated.
“The identification of the green mineral as malachite is still preliminary,” explained Tornero. “The research ongoing by the University of Granada and the Autonomous University of Barcelona will provide final answers shortly. Also, the excavation hasn’t yet reached the full depth of the site, so the sequence is not completely documented. This summer, we will continue the archaeological work.”
Reference: “Beyond 2,000 meters, first evidence of intense prehistoric occupation in the Pyrenees” by Carlos Tornero, Celia Díez-Canseco, Rosa Soler, Silvia Calvo, Selina Delgado-Raack, Chiara Messana, Julia Montes-Landa, Juan Ignacio Morales, Llorenç Picornell-Gelabert, Eni Soriano and Eudald Carbonell, 9 March 2026, Frontiers in Environmental Archaeology.
DOI: 10.3389/fearc.2026.1811493
This study was funded by the Culture Department, Government of Catalonia, Ministerio de Ciencia, Innovación y Universidades, and María de Maeztu Units of Excellence.
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