This is a fulacht fia, a type of monument found in enormous numbers across Ireland, most dating to the Bronze Age. The basic principle involves heating stones in a fire, dropping them into a water-filled trough to bring it to a boil, and using that boiling water for cooking, bathing, or craft processes such as tanning or textile work. Thousands survive as modest, often horseshoe-shaped mounds of reddened, shattered stone, their very ordinariness making them easy to overlook.

The Cooloorta example is probably U-shaped, open to the east, though vegetation has swallowed much of what the mound has to offer. The northern arm measures roughly 3.5 metres wide and 0.3 metres high; the southern arm is slightly narrower at 2.4 metres but a little taller. The western section, where the two arms would connect, is buried under bushes, and the central area, approximately 2.5 metres east to west and 1.4 metres north to south, is similarly obscured. The site appeared on Tim Robinson's map of the Burren published in 1977, which gives some sense of how long it has been recognised in the landscape, even if casually passed by. Perhaps more striking than the monument itself is the fact that another fulacht fia lies just 110 metres to the south-south-west, suggesting this wet, marginal ground beside Skaghard Lough was a place people returned to repeatedly, across what may have been a considerable span of prehistoric time.