It measures about twelve metres east to west and ten metres north to south, rising only 0.4 metres above the surrounding ground. That unremarkable profile conceals something more interesting: the mound is composed of burnt material, the accumulated debris of a fulacht fia, a type of prehistoric cooking or industrial site found in considerable numbers across Ireland and Britain. The typical interpretation is that fulachta fia functioned as outdoor cooking places, where stones were heated in a fire and then dropped into a water-filled trough to bring it to boiling point. The cracked and shattered stones, discarded after use, built up over repeated episodes into exactly the kind of horseshoe-shaped or rounded mound visible here.

What gives Knocknalyre a particular interest is not just the presence of one such site but two. A second fulacht fia lies roughly 42 metres to the east, close enough that the two were almost certainly known to the same community, and possibly used at the same time or in sequence. The pairing is not unique in the Irish record, but it is uncommon enough to prompt curiosity. Fulachta fia are generally dated to the Bronze Age, broadly between 2000 and 500 BC, though some sites have earlier or later activity. The reclaimed pasture setting at Knocknalyre is itself quietly telling: the field has been worked and improved at some point in more recent centuries, yet these two low mounds survived, either unnoticed or considered not worth the effort of levelling.