It measures roughly five metres north to south, three metres east to west, and less than half a metre high. Unimpressive by almost any conventional measure, it is in fact a fulacht fia, a type of prehistoric cooking site found in the hundreds across Ireland. The name, sometimes rendered fulacht fiadh, refers to a mound of fire-cracked stone, the accumulated debris of a process in which rocks were heated in a fire and then dropped into a water-filled trough to bring it to the boil. The technique was used repeatedly over long periods, and the shattered, heat-reddened stones were simply raked out and discarded, building up the characteristic horseshoe-shaped or oval mounds that survive today.

What gives this particular site a quiet interest is its company. Immediately to the west lies a smaller mound, apparently not composed of burnt material, whose relationship to the fulacht fia is unclear. More strikingly, a second fulacht fiadh lies approximately 130 metres to the north. The clustering of these sites suggests that this corner of north Cork saw sustained activity, with people returning to the same general area, perhaps over generations, to carry out whatever purpose these sites served. Cooking is the most widely accepted explanation, though brewing, hide-working, and bathing have all been proposed by researchers over the years. The Coolcaum example was recorded and described in the Archaeological Inventory of County Cork, Volume 4, published in 2000, which remains the principal catalogue of such finds for the region.