It measures about thirteen and a half metres north to south, nearly eleven metres east to west, and rises only twenty centimetres above the surrounding ground. To a passing eye it might mean nothing at all. To an archaeologist, it is a fulacht fia, one of the most common and yet still imperfectly understood monument types in the Irish landscape.

A fulacht fia is essentially the debris left behind by a prehistoric cooking site. The mound itself is composed of burnt and fire-cracked stone, the discarded residue of a process in which stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil. The method is thought to date broadly to the Bronze Age, though the precise purposes of these sites have been debated; cooking meat is the most widely accepted explanation, though brewing and textile processing have also been proposed. What makes the Ballyhoolahan example particularly striking is not the mound itself but its company. A survey by Bowman in 1934 recorded nineteen fulachta fiadh within this single townland alone. That density suggests sustained, repeated activity in this part of north Cork across a considerable stretch of prehistoric time, and the proximity of the mound to a stream fits a pattern seen almost universally across fulacht fia sites, where a reliable water source was essential to the whole operation.