The hill is known locally as Quern Hill, or in Irish, Carrig na mBrónta, both names pointing directly to the work once done here. A quern is a hand-operated grinding stone, the most basic form of the technology, and the fact that the local memory encoded the hill's purpose into its very name suggests quarrying here was significant enough to define the place for generations.

The hillside sits on outcrops of conglomerate sandstone, a rock type made up of coarser fragments cemented together, which gave it the hardness and texture suited to grinding grain. Quarrying extended up the southern slopes from around 800 feet to 1,300 feet above sea level, a considerable vertical spread of activity. Workers cut hollows directly into the rock to free individual stones, and the evidence of their method is still readable in the landscape: quarried hollows where finished stones were levered out, and beside them the outlines of stones that never quite made it. The abandoned pieces measure roughly 1.5 metres in diameter, about 0.3 metres thick, with a central hole of around 0.15 metres across. At that size these are substantial millstones rather than small domestic querns, intended for use in mills rather than household grinding. The site was documented by Maume in 1991, and the distribution of stones at various stages of completion gives the impression of a working quarry that simply stopped one day, leaving the hillside as a kind of open-air record of the process.

The stones in varying states of readiness are the main thing to look for: some show only the faint scoring where a cutter began to trace the circumference, others are fully shaped but cracked, which may explain why they were left behind rather than carried down. The site straddles the county boundary, so depending on the approach, a visitor crosses between Cork and Limerick without any obvious marker other than the stones themselves.