It measures only nine metres across and rises less than a metre from the surrounding ground. What makes it quietly arresting is the company it keeps: an Ordnance Survey Ireland trigonometrical pillar planted on its summit, marking an elevation of 586 feet, and the knowledge that this modest earthwork sits within a hilltop enclosure that was already old when the surveyors arrived. The mound itself is a barrow, a type of prehistoric burial monument constructed from heaped earth or stone, and its flat top and circular form are characteristic of the type found across Ireland from the Bronze Age onward.

The site at Knockbrack forms part of a larger barrow cemetery, a grouped cluster of such monuments, identified by Keeling in 1983 as Site III of an extensive complex in the area. The enclosure surrounding it, recorded separately in the national monuments register, suggests the ridge was a place of deliberate, organised use over a long period. What little disturbance has reached the mound's interior came not from excavation but from the accidental: charcoal deposits were encountered near the centre during the burial of a sheep, a discovery noted by Hartnett in 1957. The charcoal hinted at something older beneath the surface without giving much away. More recently, a geophysical survey carried out by The Discovery Programme, using non-invasive ground-scanning techniques, revealed extensive remains in the vicinity, suggesting the visible mound represents only a fraction of what lies below the ridge.

The mound sits within land under tillage, so access will depend on the agricultural calendar and, likely, landowner permission. The gorse growth around the square-shaped base of the mound provides a natural buffer of sorts, and makes it easier to pick out against the surrounding field. The views from the ridge are genuinely disorienting in their reach: the Mourne Mountains to the north, the Dublin and Wicklow ranges to the south, Lambay Island to the east, and open country stretching westward. It is the kind of vantage point that explains, without any further argument, why people chose this particular ridge to mark, gather, and bury their dead.