It is a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, and one of the most common yet least discussed monuments in the Irish landscape. The characteristic horseshoe or oval shape comes from the accumulated burnt and shattered stone that was discarded after repeated use, building up over time into a mound that outlasts almost everything else around it.

The mechanics of a fulacht fia are straightforward once explained. Stones were heated in a fire and then dropped into a water-filled trough, usually timber-lined, raising the temperature enough to cook meat or, some researchers have argued, to serve other purposes such as textile processing or bathing. The stream running along the southern side of this mound at Inishkenny would have been the water source, as is typical of the type; the proximity to running water is one of the defining features that archaeologists use to identify these sites. The mound here measures roughly 21.6 metres east to west and 11.5 metres north to south, rising to a maximum height of 1.35 metres, making it a well-preserved example of what is often a much-eroded feature elsewhere.