Cool Finds

A Century After Causing Controversy, Red Cave Markings in Wales Are Classified Again as Britain’s Oldest Rock Art

The team of scientists used modern dating methods to confirm an old hypothesis by the rock art’s initial discoverers

Sonja Anderson | Daily Correspondent

June 2, 2026 4:59 p.m.

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In 1912, scientists surveying southern Wales discovered a cave wall covered in red parallel lines. They deemed the streaks prehistoric rock art. But in 1928, other researchers disagreed, claiming the marks were naturally occurring seepages of red oxide.

Now, a modern team of researchers has backed the original hypothesis. According to a study recently published in Quaternary, someone painted the 11 red lines on the wall of Bacon Hole some 17,000 years ago. That makes them the oldest rock art in Britain—and in northwest Europe.

“It was never considered to be rock art after 1928, and also it could never be dated, because in those days they didn’t have the scientific means that we have today,” lead author George Nash, an archaeologist associated with the University of Coimbra and the University of Liverpool, says to the Guardian’s Dalya Alberge. “We’ve used uranium-thorium dating for the pigments. We’ve got data 17,100 years before present, which makes it the oldest rock art in the British Isles.”

After Bacon Hole’s red lines were dismissed as a natural phenomenon nearly a century ago, they were forgotten. As Live Science’s Kristina Killgrove reports, the scientists never specified the cave’s location. But in 2022, a team of researchers rediscovered the cave, which lies along the Bristol Channel.

The researchers determined that the red lines were painted between 18,300 and 15,700 years ago, per Live Science—stretching back into the Pleistocene. At this time, the land around the Bristol Channel was a “rich fertile plateau,” Nash tells BBC Wales’ Anna Lewis and Neil Prior. He says it would have been a “treeless landscape,” still thawing after an Ice Age, inhabited in summer by mammoths, bison, horses, elk and reindeer. And those animals likely would have drawn hunter-gatherers, some of whom may have sheltered in the nearly 100 caves lining Wales’ Gower peninsula.

In Bacon Hole, the researchers photographed and measured the red markings on the cave wall. Per the study, “the painted lines are arranged horizontally and are equidistant from one another, indicating a deliberate and structured pattern.” Researchers also identified red dots and splashes elsewhere in the cave, indicating the artist worked with their fingers.

In the lab, researchers figured out that the “paint” was a mixed pigment made of hematite—an iron oxide compound—and clay residues. The hematite was likely gathered from one area at the back of the cave, the researchers write. They affirm that the lines were “intentionally created by human agency.” But why?

As Nash tells BBC Wales, the red markings were likely practical, not artistic. “We, in our 21st-century mindset, call it art, but at 17,100 years ago, it probably was a communication system,” he says—maybe a set of tally marks, whose meaning is “way beyond our comprehension.” Still, the researchers haven’t ruled out a spiritual motivation for the painter.

They don’t know exactly how Upper Paleolithic people used Bacon Hole, Nash tells Live Science. But the fact that the rock art is located in one of the cave’s deep, dark chambers suggests it had “symbolic or ritual significance.”

“The darkness itself may have been an essential part of the ritual experience,” Nash tells Live Science. “Deep cave chambers are acoustically unusual, visually disorienting and separated from the everyday world. Entering such spaces could have created a sense of transition to a different realm.”

Previous excavations of Bacon Hole revealed pre-Roman potsherds, a Roman-era bone pin, a seventh-century Irish brooch and a medieval cooking pot, reports Live Science. And in 1894, long after the prehistoric fingerpainter left the red marks, another artist took to the cave’s walls: a local fisherman who painted graffiti that might have obscured earlier imagery, per the study.

“We always knew Bacon Hole was an extraordinary Palaeolithic site, but to discover that the oldest cave art in Britain lies here in Wales is very exciting,” says National Trust archaeologist David Thomas to BBC Wales. “To imagine people standing on this very coastline over 17,000 years ago, carving their marks into the rock and transforming the places they lived through art, is profoundly moving.”

Sonja Anderson | Read More

Sonja Anderson is a daily correspondent for Smithsonian magazine who covers art, archaeology and culture, from newly discovered artifacts to the latest art heists.