Ancient cave art discovered in south-west Ireland could push back the earliest known human presence on the island by around 5,000 years, while raising the possibility that pioneering hunter-gatherers reached Ireland from what is now Wales across an Ice Age land bridge.
Researchers have identified prehistoric artwork in eight caves in south-west Ireland that they believe dates to at least 15,000 years ago, dramatically predating the previously accepted evidence for human activity on the island.
The discoveries include engravings, ochre and charcoal paintings, and marks made by fingers in soft cave surfaces. Among the images identified by researchers are representations of animals including deer and mammoth.
The international team behind the Lost Land Bridge Project believes the finds could provide evidence that some of Ireland’s earliest known inhabitants travelled westwards from Wales during the last Ice Age, when sea levels were substantially lower than today.
An Ice Age Route Between Wales and Ireland
During the last Ice Age, vast quantities of water were locked within glaciers, lowering sea levels and transforming the geography of north-west Europe.
Researchers believe this created a broad stretch of exposed terrain between what is now Pembrokeshire and south-east Ireland, around the modern Rosslare area.
Dr George Nash of the University of Liverpool, who coordinated the Lost Land Bridge Project, estimates that the route would have formed a roughly 46-mile, or 76-kilometre, expanse between the two regions.
Rather than resembling the modern Irish Sea, the landscape would have included areas of grassland and other vegetation capable of supporting large Ice Age animals.
Wild horses, mammoths, bison and reindeer are among the herbivores thought to have inhabited such environments, feeding on vegetation able to survive the severe climate.
For mobile hunter-gatherer communities dependent on animal migration and seasonal resources, Nash argues that the landscape would have presented an opportunity that was difficult to ignore.
Discovery Could Rewrite Ireland’s Early Human History
Until now, the earliest archaeological evidence for humans in Ireland had been dated to approximately 10,500 years ago.
The newly discovered cave art could extend that timeline back to at least 15,000 years ago.
Nash said researchers had long suspected that the absence of older archaeological evidence did not necessarily mean humans had failed to reach Ireland earlier.
“Up until now the earliest evidence archaeologists had found – through accidental discovery – was from around 10,500 years ago, but everyone – not just me – knew that simply couldn’t have been correct,” he said.
“We just weren’t looking hard enough, and not in the right places.”
The project was built around a simple archaeological principle, he added: the absence of evidence should not automatically be interpreted as evidence of absence.
AI Helps Researchers Identify Promising Caves
Instead of searching Ireland’s landscape cave by cave, the researchers turned to computer modelling to narrow their search.
Working with caving specialist Shane Diffily and digital mapping consultant Darren Lee, the team compiled information about the characteristics of prehistoric cave sites in south Wales.
Those characteristics were fed into an algorithm designed to identify comparable locations in Ireland.
The model produced 28 potentially significant caves in the south-west of the country.
Researchers subsequently investigated those locations and found prehistoric rock art at eight of them.
The precise locations are being withheld because of concerns that publicity could expose the caves and their archaeological remains to vandalism or looting.
The multidisciplinary project includes researchers from University College Dublin and the University of Adelaide, as well as specialists from Wales, Portugal and Dubai.
Engravings, Paintings and Finger Marks
The newly identified artwork takes several forms, offering researchers potential insights into the artistic practices of the people who occupied or visited the caves.
Some images were engraved directly into limestone walls. Others were created using ochre and charcoal, while another category consists of lines made by dragging fingers through soft clay or sediment.
These finger markings, sometimes known as flutings, may not originally have been intended as permanent artworks. Their preservation nevertheless provides rare physical evidence of human activity inside the caves.
Researchers have also identified more recognisable animal imagery, including an engraving interpreted as depicting the front portion of a deer and another image believed to represent a mammoth.
The variation in techniques could help archaeologists understand how symbolic and artistic expression developed among prehistoric populations occupying the western fringes of Europe.
Welsh Caves Provide Important Clues
The theory of a Welsh connection is partly based on the much longer record of human occupation found across south Wales.
Nash said modern humans were present there between roughly 35,000 and 40,000 years ago, after populations moved into the region from areas including southern England, France and Spain.
Caves along the inhabitable corridor stretching from Chepstow towards St Davids provided natural shelters for prehistoric communities.
The Gower Peninsula is particularly important to the research. Some of its caves preserve evidence of human occupation stretching back tens of thousands of years, along with early examples of markings and artistic expression.
Researchers believe the artistic traditions represented by simple lines gradually developed into more figurative depictions of animals and the surrounding environment.
The Irish discoveries could represent a further stage in that tradition.
Caves Offered Refuge from Extreme Cold
Caves would have been particularly valuable during the severe climatic conditions of the Ice Age.
While outdoor temperatures could fall dramatically below freezing, cave interiors provided a considerably more stable environment. Fires near entrances and animal skins could have made them comparatively sheltered places for prehistoric groups.
That advantage may also have made suitable caves highly desirable.
As populations and family networks expanded, Nash believes competition for shelter and resources could have encouraged groups to explore increasingly distant territories.
At the same time, generations of experience following migrating animals would have improved hunter-gatherers’ understanding of the wider landscape.
Those pressures and skills may eventually have encouraged people to cross the exposed terrain towards Ireland.
Researchers Expect More Discoveries
The eight caves may represent only the beginning of a much larger archaeological story.
Although the current discoveries are concentrated in south-west Ireland, the researchers believe earlier sites could survive elsewhere along the route that prehistoric people would have taken after reaching the island.
Counties including Wexford, Waterford and Cork are considered particularly important areas for future investigation.
Nash argues that it would be unlikely for migrating groups to have crossed from Wales and travelled towards south-west Ireland without leaving evidence in areas closer to their point of arrival.
“There must be more, and even earlier places which are just waiting for us to find them,” he said.
Further investigation and dating of the sites could therefore reshape understanding of when humans first reached Ireland and how prehistoric communities moved across the now-submerged landscapes that once connected the islands.
If the findings are confirmed, they would not simply extend Ireland’s human history by several thousand years. They could provide evidence of a previously unknown chapter of Ice Age migration, when people followed animals and resources across a landscape that disappeared beneath the Irish Sea as the glaciers retreated and sea levels rose.
Header Image Credit : George Nash
Sources : Lost Land Bridge Project
