In the highlands of the eastern Pyrenees, archaeologists have discovered evidence that could transform our understanding of how prehistoric people used mountain landscapes. Located more than 7,300 feet (2,235 meters) above sea level, the cave contains dozens of ancient hearths filled with green mineral shards that may indicate early copper mining activity.
These discoveries suggest that people have repeatedly visited this remote location for about 2,000 years. The discovery challenges the long-held idea that prehistoric communities only briefly passed through high-altitude environments. Researchers also found the child’s finger bones and baby teeth, raising the possibility that the cave was used as a burial site.
“For a long time, alpine environments were seen as marginal places, places through which prehistoric communities occasionally passed,” said the paper’s lead author, Professor Carlos Tornello from the Catalan Institute of Human Paleoecology and Social Evolution. Frontiers of environmental archeology. “However, we found a very rich archaeological array, including multiple burning structures and a very large number of green mineral fragments. Although we cannot say exactly how long people stayed there each time, the repeated use of space and the density of the sites suggest that occupations of short to moderate duration were repeated over and over again over long periods of time.”
Ancient hearths and copper mining potential
This site, known as Cave 338, is located in the Fraser Valley. Archaeologists excavated an area of 6 square meters near the cave entrance and confirmed that human activity was divided into four different layers.
The most recent layers were relatively thin and contained a small number of artifacts from the historic period, suggesting that the cave was of limited use at the time. The deepest and oldest layers contained only charcoal fragments and were determined to be approximately 6,000 years old.
The most important findings came from the second and third layers. Researchers discovered 23 hearths containing large amounts of crushed and burned green mineral fragments. Although detailed testing is still underway, the material is similar to malachite, a copper-rich mineral that can be processed to produce copper.
If confirmed, the evidence could indicate that Cave 338 served as a surprisingly early high-altitude mining camp.
Co-author Dr Julia Montes Landa from the University of Granada said: “While many of these fragments have been altered by the heat, other materials within the cave have not. This clearly suggests that fire played an important role in its processing and that there was a deliberate intention behind it.” In other words, it didn’t burn by accident.
The furnaces were often stacked on top of each other, indicating that the same areas were reused over and over again. At the same time, the individual hearths remain clearly distinct, indicating that the visits do not represent a single continuous occupation, but are separated by significant periods of time.
Radiocarbon dating estimates that the second hearth is approximately 3,000 years old. The third layer of hearths is approximately 5,500 to 4,000 years old.
Children’s remains and prehistoric jewelry
Researchers also recovered human remains from the third layer, including finger bones and baby teeth of children aged at least 11 years. Although there is currently not enough evidence to determine the cause of death or whether the two bones belong to the same child, the discovery raises the possibility that additional burials may be hidden deep within the cave.
Other artifacts provided clues about the people who visited the site.
“We recovered two pendants, one made from seashells and the other from a brown bear’s tooth,” Tornello said. “They come from a prehistoric context, probably dating from around 2000 BC. The shell pendants are interesting because they have similarities at other sites in Catalonia, suggesting common traditions and connections between different communities. Bear tooth pendants are less common. It could indicate something more specific or symbolic, perhaps related to the local environment.”
Cave revisited for the first time in thousands of years
Although Cave 338 was not used as a permanent settlement, repeated returns over the millennia suggest that the site had important value to prehistoric groups.
Researchers hope future excavations will reveal more about how the cave was used and when people occupied it. They also aim to determine the exact identity of the green mineral and trace its origin.
“The identification of the green mineral as malachite is still preliminary,” Tornello explained. “The ongoing research by the University of Granada and the Autonomous University of Barcelona will give us a final answer in the near future. Also, the excavations have not yet reached the depths of the site, so its order is not fully documented. This summer we will continue our archaeological work.”

