It was only after fieldwork carried out in 2000 that the site was properly identified as a fulacht fia, one of the most common yet consistently underappreciated monument types in the Irish landscape.

A fulacht fia is a prehistoric cooking place, typically Bronze Age in date, built around a trough of water heated by dropping fire-cracked stones into it. The stones, once used, were discarded in a heap nearby, and over centuries these accumulations of blackened, shattered rock and scorched earth built up into the distinctive low mounds that survive across Ireland today. The Dirtane example is a substantial one. Earlier descriptions, working from survey records rather than ground investigation, characterised it as enclosure-like, a sub-rectangular raised area measuring roughly 18 metres by 25 metres internally and standing about 1.4 metres high. The 2000 fieldwork confirmed what lay beneath that shape: a mound approximately 20 metres east to west and just over 20 metres north to south, composed of the classic material, black earth and shattered burnt stones. The slight discrepancy between the earlier and later measurements is itself a small illustration of how much the interpretation of a site can shift once someone looks at it closely rather than from a distance.