It is roughly a metre high, eight metres wide, and fourteen and a half metres long, shaped like a horseshoe with its opening facing south. A portion of the burnt material has been quietly repurposed into a nearby field fence, which is perhaps the most Irish possible fate for a prehistoric monument.

The mound is a fulacht fia, a type of site found in extraordinary numbers across Ireland, with Cork alone containing thousands of recorded examples. The term, sometimes translated loosely as "deer roast", refers to a cooking place typically associated with the Bronze Age, though their exact purpose has been debated by archaeologists for decades. The standard interpretation involves heating stones in a fire, dropping them into a water-filled trough to bring it to a boil, and cooking meat in the resulting heat. The characteristic horseshoe shape comes from the gradual accumulation of those shattered, heat-fractured stones discarded after each use. The southward-facing opening at Rockgrove, measuring just over four and a half metres across, is a detail that distinguishes this particular example within its type, though south-facing orientations are not uncommon among fulachta fiadh generally. What is slightly unusual here is the setting: not in a field or beside a stream as is typical, but in waste ground, which suggests the surrounding landscape has changed considerably since the Bronze Age, when reliable water sources would have been essential to the site's function.