A narrow underground passage, constructed from carefully fitted drystone walling and roofed with stone lintels, now lies exposed where the earth above it has collapsed. This is a souterrain, a type of man-made underground chamber or tunnel common in early medieval Ireland, typically associated with nearby settlements and thought to have served as places of refuge, storage, or concealment. The opening left by the collapse is just wide enough to show the passage's interior: roughly 0.7 metres across, it slopes downward toward the north-east and continues in the opposite direction to the south-west, suggesting a structure of some length still buried beneath the hillside.

The site sits within, or very close to, what may be a rath, the remains of a roughly circular earthen enclosure that would once have defined a farmstead or settlement in early medieval Ireland. Such enclosures are among the most common archaeological monument types in the country, and souterrains are frequently found associated with them, constructed beneath or alongside the main living area. A large stone lintel remains in its original position within the exposed section of the passage, a small detail that speaks to the care taken in the original construction. Twelve metres to the south-west, a low circular mound of stones, about three metres in diameter and half a metre high, encloses its own area of collapse, with another substantial lintel visible at its centre. Whether this second feature represents a separate entrance, a subsidiary chamber, or an entirely distinct structure is not established, but the proximity of the two collapses hints at an underground system more extensive than what is currently visible at the surface.