To the casual eye it reads as little more than a grassy dip, roughly five metres long and just over a metre wide, but the drystone walling visible along its sides and two stone lintels still lying in place at the south-south-west end give the game away. This is a collapsed souterrain, an underground stone-lined tunnel or chamber of early medieval date, typically built beneath or beside a settlement to serve as a place of storage, refuge, or concealment.

Souterrains are often found in association with cashels, the dry-stone ringforts that were the enclosed farmsteads of early medieval Ireland, and this one is no exception, sitting within the boundary of exactly such an enclosure. The passage here ran on a north-north-east to south-south-west axis before its roof gave way. What remains is a depression between 0.3 and 0.4 metres deep, partly covered by sod and largely filled in with loose stones and domestic refuse over time. The two lintels that survive at the southern end are among the more legible details left, flat capstones of the kind that would once have roofed the full length of the passage, resting on those drystone side walls that are still visible in places along the trench.