This is a fulacht fia, a type of prehistoric cooking site found widely across Ireland, typically from the Bronze Age. The usual interpretation is that stones were heated in a fire, then dropped into a water-filled trough to bring it to the boil, and meat was cooked in the resulting heat. The mound itself is the accumulated debris of those repeated heatings, stone after stone cracked and discarded into a characteristic dark, charcoal-flecked spread. What makes Lackareagh quietly compelling is not just the preservation of the main mound, which measures twelve metres across in both directions and rises to between 0.6 and 1.5 metres externally, but the fact that it does not appear to be alone.

The main mound opens to the north with a gap roughly 5.7 metres wide, a typical arrangement that would have allowed access to the central trough area. Immediately to the east, a semicircular spread of similar dimensions may represent either an extension of the same site or a second fulacht fia altogether. A low stony hummock on the west bank of the stream, several metres to the south-west, is possibly a third. Beyond those uncertainties, three further fulachta fia have been positively identified in the immediate area, at distances of roughly four metres, seventeen metres, and one hundred and seventeen metres away. That concentration is striking. Whether the sites were used simultaneously, suggesting a community gathering place of some kind, or represent separate episodes of activity across centuries, is impossible to say without excavation, but the clustering along a watercourse is a pattern seen elsewhere in Ireland and is likely no coincidence. The site was recorded on Robinson's map of 1977, placing it within a longer tradition of landscape documentation in the Burren region.