Researchers believe the earliest known humans to reach Ireland most likely travelled from Wales, following the discovery of ancient cave art dating back at least 15,000 years, around 5,000 years earlier than any previously known evidence of people in Ireland. The find, made by an international team coordinated by rock art specialist Dr George Nash of Liverpool University, suggests early hunter-gatherers crossed a now-vanished "land bridge" that connected Pembrokeshire to south-east Ireland during the last Ice Age, when lower sea levels exposed a route across what is now the Irish Sea.

The team used artificial intelligence to identify likely cave sites, feeding an algorithm with characteristics of known cave dwellings in south Wales and applying it to search for comparable sites in Ireland. This process flagged 28 potential caves in south-west Ireland, of which eight were confirmed to contain ancient rock art, including depictions of a deer and a mammoth. Nash noted that south Wales was settled by early modern humans around 35,000 to 40,000 years ago, and that the newly found Irish art represents a further stage in the artistic progression seen in Welsh caves; the exact locations are being kept confidential to protect the sites from vandalism or looting.