A large covering stone rests on a single upright stone, known as an orthostat, with additional slabs beneath it. Two further orthostats stand immediately to the south-west, set parallel to the one that carries the covering stone. The assembly is coherent enough to be clearly deliberate, yet incomplete or damaged enough that its original form resists easy categorisation. Archaeologists have noted that some form of burial structure would not be inconsistent with what survives, but the classification remains formally uncertain, pending further investigation.

What makes Knocknagappul quietly remarkable is the company it keeps. A wedge tomb, one of the most common megalithic burial types in Ireland, typically consisting of a roofed gallery that narrows towards one end and usually dates to the later Neolithic or early Bronze Age, lies just 115 metres to the south-west. Within a radius of roughly 220 metres, two further groupings of stones have been recorded, each classed as anomalous, meaning they share characteristics with known monument types without fully conforming to any of them. Whether these sites were once part of a single ceremonial landscape, or whether proximity is simply a consequence of this particular hillside being attractive to people over a long span of time, is an open question. The southern extension of the Boggeragh Mountains offered elevated ground, natural rock exposures, and views across the surrounding terrain, qualities that repeatedly drew prehistoric communities to similar upland locations across Ireland.

The structure sits in farmland, and the surrounding outcrops of natural rock mean that identifying the man-made stones requires some attention. The wedge tomb to the south-west provides a useful point of reference for anyone trying to understand the broader pattern of monuments on this hillside, and seeing both together gives a clearer sense of how densely this landscape was once marked by its inhabitants.