That absence is, in its own way, informative. The feature belongs to a class of monument known as a fulacht fia, a term used to describe the scorched spreads of shattered stone that survive in their thousands across the Irish landscape. The standard interpretation is that these sites were cooking places, used by heating stones in a fire and dropping them into a water-filled trough to bring it to the boil, though some archaeologists have proposed other functions, from textile processing to brewing. What makes Drummin quietly puzzling is the combination of a near-sterile deposit and the stray medieval pottery recovered from the trough itself.

Excavation was carried out in 2000 by archaeologist Donald Murphy. The burnt stone spread measured approximately 14.5 metres east to west and 8 metres across, with a consistent depth of around 0.2 metres, a substantial accumulation suggesting repeated use over time. Immediately to the south of this spread lay an irregularly shaped pit measuring roughly 1.05 by 1.4 metres, the kind of feature that typically served as the water trough at the centre of a fulacht fia's operation. When the burnt spread was removed, no further archaeological features appeared beneath it, which means the site left little trace of whatever activity generated all those shattered stones. Two sherds of medieval pottery came from the fill of the trough, a small but telling detail. Fulachta fia are generally associated with the Bronze Age, so the presence of medieval material in the trough suggests either later disturbance or reuse of the hollow long after its original purpose had been forgotten.