The Palaeolithic was the age of the earliest humans, the Neanderthals who spread out from Africa and inhabited Europe before the Ice Age and their successors and the Cro Magnon Man humans who created the famous cave paintings at Cheddar Gorge in England, Altamira in Northern Spain and Lascaux, Niaux, and elsewhere in France.
The Palaeolithic or Old Stone Age is the single longest period of human and hominid prehistory, beginning some 2.6 million years ago with the discovery and use of the oldest and most primitive stone tools in the Great Rift Valley in modern east Africa (http://geology.com/articles/east-africa-rift/figure2.jpg). Palaeolithic peoples are known to have been present in Britain perhaps as far back as 814,000 years ago. However, while early Neanderthals lived in what is now Wales some 230,000 years ago and modern homo-sapien settlement has been identified in upper Palaeolithic deposits in Wales dating to c.27,000 BCE, there are as yet no known Palaeolithic sites in Ireland. Three Palaeolithic artefacts have been discovered in Ireland however, the most recently discovered is a 200,000 year old flint flake known as a Levallois rejuvenation flake, discovered on a drumlin in Ballycullen, Newtownards Co Down on the northern side of Scrabo Hill. A similar Levallois Flake was discovered in a glacial deposit in a quarry at Mell, Drogheda, Co Louth in 1968. The earliest Palaeolithic artefact discovered so far was a hand-axe c.300,000 years old, discovered at Dun Aengus on Inishmore in the Aran Islands although this may have been deposited on Aran long after its fabrication.