The method involved lighting fires against a rock face to heat and crack it, then dousing it with water or simply letting it cool, allowing miners to work loose material that would have resisted iron tools alone. That such evidence survives here at all, legible in the stone, is what lifts this spot out of the ordinary.

The adit, roughly four metres wide, one and a half metres high, and about four metres deep, slopes downward to the south into the hillside. Immediately to the north, a low, largely turf-covered mound has been slowly spilling its contents down the incline: heat-shattered stones and damaged stone mauls, the latter being heavy rounded rocks used as hammers to pound and break ore-bearing rock. These are the signature debris of prehistoric copper mining, and their presence alongside the fire-setting traces points to activity that may well predate the use of metal tools entirely. A further small opening, blocked by rubble, sits about two metres to the east and may mark the entrance to a second adit. A separate copper mine lies roughly forty-five metres to the south, suggesting that this particular hillside was worked across more than one location, part of a concentrated effort to extract ore from the valley's rocky ground.