Dr George Nash from Liverpool University has identified eight cave locations across south-west Ireland containing rock art that dates to at least 15,000 years ago.
This finding pushes back the known timeline for human activity in the region by approximately five thousand years compared to previous records.
The research team, which includes specialists from University College Dublin and the University of Adelaide, also incorporated experts based in Dubai, Wales and Portugal.
Dr Nash stated that the environmental conditions during this period created a viable route connecting Wales and Ireland.
He described the area as a forested and grassland plateau stretching roughly 46 miles across the landmass.
According to Dr Nash, summer temperatures in this zone would have ranged between -10°C and -20°C.
The terrain supported large herbivores such as wild horses, mammoth, bison and reindeer that grazed on sedges, mosses and lichens growing through the nutrient-rich soil.
Dr Nash noted that hunter-gatherers would have found these resources too attractive to overlook.