Few pause to notice the twenty-six small cave openings that punctuate the mountain's steep north and north-western slopes. One of these, a narrow cruciform passage just 14.5 metres long, a metre wide, and scarcely tall enough to stand in, turns out to contain evidence of human activity stretching back roughly five thousand years.

In 2002, researcher Stefan Bergh found a fragment of occipital bone, the curved plate at the base and rear of the skull, lying on the cave floor about eight metres from the entrance. Radiocarbon dating placed it at 4,740 plus or minus 50 years before present, firmly within the Neolithic period, the era of early farming communities in Ireland, roughly 4000 to 2500 BC. The find was not isolated. Approximately fifty metres to the north-west, a second cave on the same slopes, designated Cave K, has also yielded Neolithic human remains, as reported by Dowd and Kahlert in 2014. What precisely these bones represent is not straightforward to interpret. They may be the remnants of formal burial practices, or they may reflect other, less easily categorised uses of underground space by Neolithic people. Either way, the caves sit on the same mountain that was clearly significant to prehistoric communities over a very long period, and the accumulation of evidence across multiple cave sites suggests this was not accidental or incidental use of the landscape.