ROCK ART could be described as human made markings found inscribed into the landscape on rocky outcrops or passage tombs.

In Ireland it flourished around the later 4th and 3rd millennia BC, so during the Neolithic. It was a significant period notable for the arrival of farming and the building of the megalithic stone tombs. These marking though could be of an earlier date and the practice may have continued over a longer period. 

But they were rich with symbolism, mostly still a mystery to this day. Were they territorial, markers to sacred sites, star maps (see Sess Kilgreen), all of the above? They were a global phenomenon and the markings we see today e.g spirals, zigzags found in some passage tombs are still being used today. 

The millennia might separate us but we are connected by the same instinctive mark making.

Check out the following sites for more information:

Search Results | National Monuments Service (archaeology.ie)

Scotland's Rock Art Project | Historic Environment Scotland | HES (This mostly refers to Scottish research but is of great interest)

Loughnashee Rock Art | A miscellany of places | Our Irish Heritage