The site at Kildarra is a fulacht fia, the term used for a type of prehistoric cooking or heating site found in great numbers across Ireland, typically consisting of a burnt-stone mound and an associated water trough. They are among the most common archaeological monuments on the island, yet each excavation tends to yield its own particular details, and this one is no exception.

Archaeological monitoring of the Lough Mask Regional Water Supply Scheme between 2001 and 2002 led to the discovery and full excavation of the site. What emerged was an irregular spread of heat-shattered sandstone and some limestone fragments, measuring roughly 5.3 metres north to south and 2.3 metres east to west, set within a matrix of charcoal-rich peat. The mound had been disturbed at some point in the past, but enough survived to make sense of the original layout. Approximately 1.3 metres east of the burnt stone, a subcircular trough had been cut directly into the underlying boulder clay, with steep sides, a flat base, and dimensions of about 1.2 metres long, 0.7 metres wide, and 0.62 metres deep. The trough fill contained alder wood chips, a degraded timber post, and two fragments of burnt bone too deteriorated to identify. On the southern edge of the trough, a blackthorn post roughly five centimetres in diameter had been driven into the ground and survived in a reasonable state of preservation. A short distance away, around 2.5 metres to the south-east, a cluster of smaller timber posts arranged in an arc pointed to some kind of additional structure or enclosure, the precise function of which remains unclear. Radiocarbon dating of a charcoal sample placed the site in the range of 800 to 409 BC, placing it in the latter part of the Late Bronze Age. Notably, a second fulacht fia was identified just 50 metres to the south, suggesting the area saw repeated or sustained use during this period.