The site at Knocknageehy is what was once known as a cillín, an informal burial ground set apart from consecrated parish cemeteries, where unbaptised infants and others excluded from official Church burial rites were interred. The Ordnance Survey six-inch map of 1842 labels it plainly as a Children's Burial Ground, a designation that makes its purpose clear even as the ground itself offers almost no visible trace of who lies there.

The knoll itself defines the site as much as any built boundary does. The scarped, or cut-away, edges of the rocky outcrop form a natural enclosure roughly oval in shape, with only fragmentary traces of a stone wall surviving to the north-east. No grave markers have been recorded anywhere within the area. At the southern edge stand the ruins of a church, and just outside the north-east corner of its chancel, the base of a cross survives at ground level. A low rectangular mound nearby, standing roughly half a metre high and measuring three metres by two, has some facing stones still visible and may mark an individual grave, though nothing confirms it with certainty. The association of the children's burial ground with an earlier ecclesiastical site is not unusual in Ireland; many cillíns occupy ground with older religious connections, perhaps because such places were understood to carry some residual sanctity even after formal worship had ceased.

The knoll commands views in all directions, which gives the site an unexpectedly open quality for somewhere so quietly set aside from ordinary life. The absence of any gravestone or inscription means the ground reads as almost empty, and yet the combination of the church ruins, the cross base, and that ambiguous low mound makes it one of those places where the archaeological record and the human story press close together without quite resolving.