The mound measures roughly eleven metres east to west and eight metres north to south, rising only about thirty centimetres for most of its extent but reaching closer to eighty centimetres along its northern edge. At its eastern end, a lower and less distinct rise extends out to the north-east, lending the whole structure a roughly crescentic form, open to the north-west. Beneath the grass, the mound is composed of stone fragments packed into dark brown and black soil, the characteristic burnt and waterlogged debris that accumulates at these sites over repeated use.

A fulacht fia is a type of prehistoric cooking place found in great numbers across Ireland, typically Bronze Age in date. The usual arrangement involved a trough dug into the ground, filled with water, and heated by dropping fire-cracked stones into it. Those spent stones were piled to the side after each use, gradually building up the horseshoe or crescent-shaped mounds that survive today. The dark, charcoal-rich soil and shattered stone seen at Gortaskibbole are exactly what this accumulation looks like after centuries of burial. The adjacent expanse of reclaimed wet ground fits the pattern well, as these sites were almost always placed near a reliable water source. About fifty metres to the south, on the ridge above, there is a separate enclosed site, suggesting this was not an entirely isolated spot in the prehistoric landscape.