Mysterious Green Rocks Discovered in a Remote Cave in Spain Might Be Signs of Prehistoric People Working With Copper

Maria D. Guillén / IPHES-CERCA To get to Cave 338, high in the Pyrenees mountains, you must go primarily by foot. That’s exactly what a team of archaeologists did during a recent excavation—and likely exactly what people did thousands of years ago, when the area may have served as a copper processing site.

A new study published this week in Frontiers in Environmental Archaeology found hearths, jewelry, children’s bones and a green mineral that researchers think is malachite, a mineral that is a source for copper.

Previously, archaeologists thought that prehistoric peoples in that region rarely spent time at high altitudes. But this new discovery proves otherwise.