It does not appear on Ordnance Survey maps. You could walk directly over it without any indication that a carefully built stone room lies just beneath your feet, its slab roof intact, its side-walls still coursed in flat, regular stone after what may be well over a thousand years.

This is a souterrain, a type of underground passage or chamber found widely across early medieval Ireland, typically associated with nearby settlement and used variously for storage, refuge, or both. The entrance here is modest, a rectangular opening roughly 80cm by 60cm, leading down three stone steps to a lintelled passage and then into the main chamber, which runs north to south for just over three metres and stands about 1.2 metres high. Around the entrance, a semicircular bank encloses the approach, with a stretch of well-built stone facing visible on its inner side, though now largely swallowed by vegetation. Whether this represents the remains of an associated hut or connects to something else is unclear. Until the late 1930s, the whole structure was covered by a low cairn, a mound of stones, which was apparently removed around 1937. A researcher named O'Connell, working with the Office of Public Works, noted that iron-slag had been recovered from the stones of that cairn, and that a large, heavily scored stone had been found directly over the entrance. Both details hint at activity and use beyond simple storage, though what exactly took place here remains an open question. The sooty coating on the chamber walls adds a further layer of ambiguity; fire or smoke was present at some point, though in what context is not recorded.

The chamber floor is usually flooded and appears to slope downward toward its southern end, so any attempt to enter would be a damp and cramped undertaking. Collapse and accumulated debris have built up at the base of the steps. The site carries a preservation order under the National Monuments Acts, which means it is legally protected, and the surrounding vegetation has done its own quiet work of concealment in the decades since the cairn was cleared away.