It measures roughly fourteen metres north to south and thirteen metres east to west, rising only about seventy centimetres from the ground, with a westward-facing opening just over three metres wide. Unassuming from a distance, it is in fact the remains of a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, typically dating from the Bronze Age.

Fulachta fia, the plural form, are generally interpreted as outdoor cooking places where water was heated by dropping fire-cracked stones into a trough. The stones, once used, were discarded to the sides, building up over time into the characteristic horseshoe or kidney-shaped mound of blackened, heat-shattered material that survives today. The westward opening at Curraglass would originally have allowed access to a central trough, now absent or no longer visible as a feature. A drain runs along the western edge of the mound, and a recent depression has appeared in the southern arm, suggesting some degree of ongoing disturbance or subsidence. Thousands of these sites are known across Ireland, but each one represents repeated episodes of activity by people who left almost no other trace in the landscape.