It is a fulacht fia, a term used to describe the burnt-mound remains of ancient cooking or industrial activity. The typical fulacht fia consists of a horseshoe-shaped or kidney-shaped mound of fire-cracked stone, built up over time beside a water source. The prevailing interpretation is that stones were heated in a fire and dropped into a water-filled trough to bring it rapidly to the boil, with the cracked, discarded stones accumulating into the mound that survives today. These sites date broadly to the Bronze Age, roughly 1500 to 500 BC, though some examples fall outside that range.

The location at Knockadooma fits the pattern closely. Fulachtaí fia are almost always found near running water or in low-lying, boggy ground, both because water was central to their function and because the damp conditions have helped preserve the organic and structural evidence over millennia. The marshy setting beside a stream, while making the site difficult to approach, is precisely what one might expect, and in a broader sense, what has allowed it to survive at all. West Cork has a notable concentration of these monuments, scattered across townlands that were once far more densely worked and inhabited than their present quietness suggests.