It is not a medieval mine, nor an early modern one. Radiocarbon dates place its use firmly in the Bronze Age, around 1670 to 1660 Cal. B.C., making it one of the earliest known copper mines in Ireland and among the oldest in Europe. The entrance, roughly three metres wide and less than two metres high, opens into a slightly narrower interior that rises to a more generous height, a geometry that suggests deliberate, methodical cutting rather than opportunistic scratching at the rock. Outside, the spoil dump, the waste material thrown clear during excavation, still spreads across approximately 170 square metres on a natural ledge, in places nearly two metres deep.

Excavation of the peat that had built up inside the mine over the millennia uncovered what the Bronze Age miners actually left behind: stone mauls, the rounded hammer-stones used to pound ore loose from the rock face, and wooden implements whose survival in the waterlogged sediment was a minor miracle of preservation. The mine itself is what archaeologists describe as a transition from a strata-bound drift mine, one that follows a seam along its natural line, to a cross-cutting tunnel, meaning the workings eventually broke across the grain of the rock in pursuit of the ore body. To the south of the entrance, excavation also revealed a water trough, a post-hole structure that once supported some kind of timber construction, concentrations of additional stone mauls, and a careful arrangement of stone slabs. Taken together, this amounts to a picture of an organised working site, not a casual or temporary one. The research cited is attributed to O'Brien, 1987.

The mine is flooded today, so the interior cannot be explored, and the site carries a preservation order under the National Monuments Acts. What remains visible above ground, principally the spoil heap on its ledge and the scarred face of the rock outcrop, sits about 27 metres north of an eastward-flowing stream on the slopes of Mountgabriel. The sheer depth of the spoil dump alone, built up by people working with stone tools more than three and a half thousand years ago, gives some measure of how seriously this hillside was once worked.