Thierry Aubry highlights the outline of an aurochs motif on Penascosa Rock 3

Benjamin Taub

It’s 6am at the Penascosa rock art site in Portugal’s Côa valley, and under the raking glow of torchlight, a faded carving of an aurochs – a wild ox that lived during the last glacial period – suddenly comes into focus against the pre-dawn gloom. For three weeks, archaeologist Thierry Aubry from the Côa Park Foundation and his team have been digging beside the engravings in search of ancient tools that might help them understand the function of the valley’s oldest rock art. As we enter the final day of excavations, they have finally found what they are looking for: thumbnail-sized slivers of razor-sharp stone that were used as hunting weapons by prehistoric hunter-gatherers.

“This technology is typical from 26,000 years ago”, says Aubry in a voice tinged with excitement and relief. “It’s the first time we’ve found material this old next to the art.”

Finding these artefacts just a few metres from one of the most significant rock art panels in the entire Côa valley helps to demonstrate that art wasn’t just something our ancestors placed at remote sacred sites, but was “part of daily life”, says Luís Luís from the Côa Park Foundation.

Within the archaeological layers containing the stone bladelets, researchers also found the remains of other flaked tools as well as hearths, indicating that people made fire and used a range of utensils within touching distance of the engraved panel. Or, as Aubry puts it, “they were living inside the art”.

The stone tools at Penascosa provide vital clues about the social context in which the rock art was created and viewed, revealing how it shaped the encounters between groups of people who migrated to Côa to hunt and interact. “The most logical function is to transmit some mythology, but also to transmit some practical information for hunters,” says Aubry.

Thierry Aubry examines some 26,000-year-old bladelets from Penascosa

Benjamin Taub

The Côa valley is the largest open-air collection of Palaeolithic rock art in the world. The engravings, which were first discovered in 1991, are spread over some 17 kilometres of river valley. “Art preserves well in caves, but not in the open air,” says Luís. “But here in Côa, we have conditions that allowed open-air art to be preserved, because it’s a dry region and the local schist is very resistant to erosion.”

The discovery of these exposed motifs triggered what Luís calls a “Copernican revolution” in archaeology by proving that rock art wasn’t restricted to the dark underground settings associated with religion and ritual, but was often a very public phenomenon.

“The Côa valley discovery prompted people to search for similar stuff elsewhere, and now we know from the last 30 years of discoveries that, in fact, it must have been all over the place,” says João Zilhão at the University of Lisbon in Portugal, who set up the Côa Valley Archaeological Park in 1996. Since then, further open-air sites of Palaeolithic rock art have been identified across the Iberian peninsula and beyond, with stylistically similar engravings found as far away as the Nile valley.

At Côa, the earliest phase of rock art production corresponds to the transition between the Gravettian and Solutrean periods of the Upper Palaeolithic, some 26,000 to 27,000 years ago at the onset of the last glacial maximum. To understand why hunter-gatherers chose to fill this valley with engravings 10,000 years before the Lascaux cave paintings in France were made, researchers have spent the past three decades searching for signs of occupation during the late Gravettian at Penascosa.

“In 1995, everybody said it would be impossible to find this because it’s an open-air site and it’s right by a river, so everything will have been washed away [during flooding events],” says Aubry. “But if you don’t look, you don’t find.”

The first attempt to find evidence of an ancient campsite was overseen by Zilhão. Yet by the end of the last major round of excavations, which Aubry led in 2018, layers showing signs of human occupation still hadn’t been found. In 2025, however, a test pit dug right in front of Penascosa’s Rock 3 – which is engraved with a series of overlapping animal motifs – revealed a number of fire-damaged rocks and flaked stone tools that match the style of the late Gravettian and early Solutrean.

For the first time, the team had direct evidence of people sitting around fires and manufacturing survival technologies at Penascosa, just as the landscape was being monumentalised through rock art. “What this shows is that the hunter-gatherers of the Palaeolithic were just like the hunter-gatherers of today,” says Zilhão, referring to certain Aboriginal Australian communities who continue to use rock art in a similar way. “They decorated the territory they lived in.”

A reassembled tool made from three stone flakes from Penascosa, thought to be 26,500 years old

Thierry Aubry / Fundação Côa Parque

Returning to Penascosa last month to excavate this prehistoric living room, the team uncovered buried slabs of schist that had once formed a natural overhang, beneath which ancient hunter-gatherers had taken shelter until the heat from their campfires caused it to collapse. Digging through the layers of time, the archaeologists unearthed a sequence of artefacts that traced the course of human history from the Palaeolithic all the way up to Roman times. Unlike western Europe’s famous painted caves, then, the Côa valley and its rock art didn’t remain sealed off from the ever-changing outside world, but provided a stage for the social dramas that shaped the lives of ancient Iberians for millennia.

Eventually reaching the 27,000-year-old Gravettian occupation layer just as time was running out on the dig, the archaeologists uncovered the evidence they needed to orient Penascosa – and its earliest engravings – within the social landscape of ancient Iberia.

“This flint comes from central Spain, at least 150 kilometres away,” says Aubry, holding a tiny bladelet from Penascosa. “But this flint is from central Portugal, 200 kilometres the other way,” he says of another bladelet that was found in the same deposit. The convergence of these far-flung materials at this one spot suggests that, 27,000 years ago, the Côa valley sat at the heart of a vast network of exchange that spanned half of Iberia.

“This also explains why the art here is so similar in style to what you see in northern Spain, or even as far as the Rhône valley in France,” says Zilhão. These similarities, he suggests, indicate that rock art functioned as “a shared code of representation” belonging to “a network of people that exchanged information, personnel and objects, forming a very widespread area of cultural homogeneity”.

Yet the Côa valley may have been more than just another node in this network. “This region is a natural border between the [Atlantic] coast and the Iberian interior, so we think it was an important meeting place for populations from these different areas,” says Luís. For decades, archaeologists at Côa have argued that the valley was a social aggregation site, where bands of hunter-gatherers from across the Iberian hinterland periodically came together to meet and hunt. “The lithic materials give us that information,” says Luís. “We no longer see these populations as isolated.”

The valley’s rock art can therefore be understood as a key component of the social world that gave rise to it, in which highly mobile bands of hunter-gatherers repeatedly came face to face at Côa. In other words, as Luís says, “the art was used in moments when distant groups came together”.

Thierry Aubry points out the individual animal motifs within a composition featuring multiple overlapping animals at Fariseu

Benjamin Taub

To highlight the role that rock art may have played in these encounters, Aubry takes me to Fariseu, another of the valley’s decorated sites. Here, archaeologists have found evidence that hunter-gatherers repeatedly lived among the artworks – although, unlike at Penascosa, they are yet to discover occupation layers dating to the late Gravettian, when the site’s earliest engravings were made.

“It’s a story, with a beginning, a middle and an end – like 16th-century art,” says Aubry as we stand before one of Fariseu’s engraved panels. “But I don’t think it was meant for the people from here. It was for people coming from other regions.”

On the rock face is a repeating series of motifs consisting of four female aurochs, each accompanied by a calf and apparently moving towards the nearby river. “One function was probably to establish a relationship with these animals, to show to people from other places that you are from a particular group,” says Aubry. This notion chimes with one presented by other scholars, who suggest that the Côa valley artists may have used animal motifs to represent humans.

Yet these engraved narratives may also have conveyed information about large herbivores and how to hunt them. The aurochs calves, for example, all appear to be around 6 months old, leading Aubry to speculate that the composition may depict the animals’ behaviour “at a specific moment in the year”.

“I think the aggregation moment was probably a hunting moment,” he says. “So the transmission of mythology was the social function [of the rock art], but the hunting function was also essential.” Rather than separating the symbolic from the practical, then, the same images could have performed both functions at once.

“Obviously it’s very difficult to understand the meaning of the art, but it may have been part of a survival strategy,” says Luís. As travellers and locals met at Côa’s engraved sites, the images they created may have facilitated vital exchanges between bands of strangers while also enabling them to hunt together.

“Côa revolutionised everything, because it made many of us realise that this is normal Ice Age art,” says freelance archaeologist Paul Bahn, who isn’t involved in the excavation. “I always assumed that they were living very close to the art, if not in the art sites themselves, so I’m delighted that they’ve finally got evidence of that.”

For more than three decades, discoveries in the Côa valley have helped to reshape the perception of Palaeolithic rock art from something produced exclusively in caves for ritual purposes to something that was often outdoor and multifunctional. “The vast majority of it was in the open air, and the stuff in caves was almost a marginal phenomenon,” says Bahn. “It just happens to have survived much better.”

To truly understand such art, though, Aubry says we must stop studying it as a distinct phenomenon and view it instead as an integrated component of the everyday world of ancient hunter-gatherers. “Archaeologists need to realise that we are not studying a monument,” he says. “We are studying people living in a space.”