It is not much to look at, and that is precisely what makes it worth understanding. This small notch in the stone is a prehistoric copper mine, worked not with metal tools but with fire.

Fire-setting was the principal technique used by early miners across Bronze Age Europe. Timber would be burned against the rock face to heat it, after which cold water or simply the cooling air would cause the stone to fracture, allowing ore-bearing material to be extracted. The dimensions recorded here, less than a metre in length, 1.8 metres wide, and 1.45 metres high, suggest a working face that was opened, exploited, and then effectively abandoned without accumulating the debris one might expect. There is no surviving spoil sediment, the waste rock that typically accumulates outside a mine entrance, and no stone mauls, the rounded hammer-stones that Bronze Age miners used to break and dress ore, have been found at the site. Whether those traces were always absent or have simply not survived is unclear, but the fire-worked face itself is the key evidence. The site sits approximately 14 metres east of a related mine and forms part of a cluster of ancient workings in this corner of west Cork, documented by archaeologist William O'Brien in 1987.