A caher is a ringfort built entirely of dry-stone masonry rather than earthen banks, and this one near Killagurteen is unusually well preserved given how thoroughly vegetation has swallowed it. Its enclosing wall, still standing to 1.5 metres on its outer face, is 2.3 metres wide and constructed in the classic manner: two dressed stone faces packed with a rubble core. A low internal step, or terrace, runs along the inner face of the wall, varying in height from 0.3 metres in the north-west to 0.7 metres at the south. At the north-north-west, two stone slabs protrude from the inner wall-face at heights of 0.77 metres and 0.92 metres above this terrace, almost certainly serving as footholds to allow someone to climb up and look out over the wall-top.

What makes this caher particularly interesting is a feature built into the north-west section of its wall: a mural chamber, a small room constructed within the thickness of the wall itself. To fit it in, the wall was widened somewhat at that point. The chamber's entrance, set in the outer wall-face, is trabeate in form, meaning it is topped with a flat lintel rather than an arch, and it narrows from 1.45 metres high at the base to just 0.45 metres wide at the top, giving it a slightly wedge-shaped profile. Inside, upright slabs line the base, the walls are regularly coursed and slightly corbelled inwards, and large lintels form the roof. The chamber measures 1.75 metres by 1.25 metres with a height of 1.54 metres, enough for a person to crouch or sit, though its precise function remains uncertain. In the south-west quadrant of the interior, the collapsed remains of a circular stone hut survive, roughly 3.8 metres across internally, along with an L-shaped trench whose stone-collapse fill and surviving stretches of coursed walling suggest it is the souterrain recorded at the site by O'Connell in 1939. A souterrain is an underground passage or chamber, typically cut into the earth and lined with stone, associated with early medieval settlement and used variously for storage, refuge, or ventilation. The main entrance to the caher, also at the south-west, is partially collapsed and narrows to just over half a metre wide, a tight squeeze even before the stonework began to shift.