A fulacht fia, broadly speaking, is a type of burnt mound, typically consisting of fire-cracked stones and charcoal-rich debris left behind after repeated cycles of heating stones and plunging them into water-filled troughs to cook meat or process other materials. They are among the most commonly recorded prehistoric monuments in Ireland, yet each one carries the faint imprint of people who worked and ate beside it.

This particular site sits on a very gentle east-facing slope, positioned beside a stream, which is entirely characteristic of the type; access to running water was essential to how these sites functioned. Only a portion of it is currently visible, exposed by ploughing across an area measuring roughly ten metres east to west and four metres north to south. The rest of the site appears to continue southwards into the overgrown and unploughed verge that flanks the stream, meaning the full extent remains obscured beneath vegetation and undisturbed ground. The burnt stone material here is notably dense with charcoal, and shares its character with a second burnt spread located around two hundred metres to the west, with one distinction: the Coolnakilly site contains quartz among its fire-cracked stone assemblage, which sets it slightly apart from its near neighbour.