The feature at Ardrum consists of a flat circular area roughly ten metres across, enclosed by an earthen bank about half a metre high. Modest enough on its own, but its classification has quietly shifted over the decades from prehistoric cooking site to something more ambiguous, and rather harder to categorise.

When P. J. Hartnett examined the site in 1939 and published his findings, he identified it as a fulacht fiadh, a type of prehistoric cooking pit typically associated with the Bronze Age, where water was heated by dropping fire-cracked stones into a trough. They are common across Ireland and often survive as horseshoe-shaped mounds of burnt stone. This one, however, yielded no supporting evidence for that interpretation when looked at more carefully. The 1939 Ordnance Survey six-inch map had already recorded it as a small circular mound within the demesne of Ardrum House, and the current thinking is that it belongs instead to the designed landscape of that estate, an artificial or ornamental earthwork rather than a remnant of prehistoric activity. The woodland around it was cleared around 1984, and the site is now heavily overgrown. About 150 metres to the south-east there is a similar circular feature and a standing stone, which adds a further layer of uncertainty to how this corner of the demesne was laid out and used.