It measures roughly nine and a half metres across in both directions, irregular in shape, and it represents a type of site found in considerable numbers across Ireland: the fulacht fia. The term, sometimes translated as "cooking place of the deer," refers to a Bronze Age hearth and trough arrangement where stones were heated in fire and then dropped into a water-filled pit to bring the contents to a boil. Over time, the thermally fractured stone accumulates into a horseshoe-shaped mound, and it is precisely this spread of burnt material that survives at Liskillea.

Sites of this kind date broadly to the Bronze Age, though some continue into the early medieval period, and their function has been debated by archaeologists for decades. Cooking is the most widely accepted explanation, though brewing, bathing, and hide-working have all been proposed. What makes the Liskillea example quietly notable is a detail passed down through local knowledge: a well that once stood beside the site has been filled in. Water is central to how a fulacht fia would have operated, and the proximity of a well suggests this particular spot was chosen deliberately, the landscape shaped around a reliable water source that has since been closed off. The mound remains, but the practical logic that once anchored it to this specific hillside has been erased.