The one at Dromnacaheragh came to light not through archaeological excavation but through the far more ordinary business of widening a farm road, when the north-facing entrance opened up at the base of a field bank roughly two and a half metres high. It is the kind of discovery that quietly reframes a working agricultural landscape: what looked like an unremarkable slope in pasture turned out to conceal a subterranean structure that had been waiting, sealed and largely intact, beneath the soil.

The entrance, just 1.2 metres wide and 0.8 metres high, leads into an earth-cut chamber with a rounded roof that extends at least 3.5 metres in a south-easterly direction, its floor scattered with collapsed earth and stones. Off the north-east side of this chamber, a creepway barely 0.6 metres wide and 0.4 metres high, framed by two upright jambstones supporting a stone lintel, connects to a second chamber that has not been entered due to safety concerns. The dimensions throughout are notably tight, designed for someone to move through on hands and knees rather than to stand. That narrowness was almost certainly deliberate: a creepway so small is easily defended and difficult for an intruder to pass through quickly, which supports the idea that these structures served as places of concealment during times of threat, as well as for the cool, stable storage of perishables.