Fire-setting, one of the oldest known methods of hard-rock extraction, involved lighting fires against the mine face to heat and crack the stone, after which miners would pound the loosened rock with cobble hammers called mauls. No chisels, no explosives, no iron. The smooth, domed interiors of these workings are the direct result of that process, and broken mauls still litter the spoil heaps outside the entrances today.

Radiocarbon dating has placed the activity at this complex between approximately 1700 and 1500 cal. BC, during the early Bronze Age, with no evidence that the mines were ever reopened or reused in later periods. The complex comprises 31 confirmed or possible mining sites, twenty-seven of which are in State care, and together they represent what researchers classify as Mount Gabriel-type mines, considered among the most significant early mining groups anywhere in Europe. William O'Brien, whose 1994 monograph examined the site in detail, identified two consistent features of each working: the drift mine itself, a shallow inclined opening that followed the mineralised rock outcrop down from the surface, and the spoil dump outside, where ore was crushed and sorted by hand. The mines range from surface openings of less than a metre in depth to underground shafts reaching inclined depths of up to eleven metres. Despite the scale of the operation implied by thirty-one separate workings, no associated smelting furnaces or settlement sites have yet been located.

The most tangible traces for a visitor are the spoil dumps, large mounds of loosely packed rock debris heaped outside the mine entrances. These are rich in charcoal and scattered with the remnants of the stone mauls used to break the ore. The mine openings themselves, where accessible, show that characteristic smooth interior profile, a quiet but precise record of a process carried out here over three thousand years ago.