This is a caher, the Irish term for a stone-walled ringfort as distinct from an earthen one, and it comes with a souterrain threading through its interior: an underground passage built without mortar, its stones laid dry, winding in a U-shape beneath the enclosure floor and eventually passing out under the enclosing wall itself.

The caher measures roughly 16 metres across internally. Its eastern half is almost entirely lost to vegetation, but the western arc of wall survives well enough to reveal something genuinely unusual: two distinct building traditions in a single structure. At the south-west, the wall is carefully faced on both sides with coursed slate slabs packed around a rubble core, while further round to the west the facing shifts to larger, blockier slabs laid in rougher courses. The wall here stands about 1.5 metres high on its outer face and nearly 3.8 metres wide, with an intermittent basal step along the exterior that appears not to be bonded into the main fabric, suggesting it may belong to a separate phase of work. A heavily eroded gap about a metre wide survives at the south-south-west, likely the original entrance.

The souterrain is the site's most intricate element. A souterrain is a roofed underground passage, typically associated with early medieval settlement in Ireland, and this one enters through a small opening in the enclosing wall before branching through a sequence of passages running north-east, then east, then north, then west, accumulating to well over ten metres of mapped corridor. Many of the roofing lintels have been removed or have collapsed, and the passage becomes progressively narrower and lower as it extends northward, eventually dropping in floor level and filling with sediment. At its furthest accessible point, where it widens beneath the base of the enclosing wall, a tiny external opening of just 50 by 20 centimetres pierces the wall's outer face. Whether this was a ventilation slot, a drainage point, or a deliberate feature of the design, it gives the whole structure a quality of careful, hidden purpose that the surrounding forestry only deepens.