It lies on a south-facing slope of rough grazing land, having toppled at some point, and now measures just under one and a half metres in length with a roughly rectangular cross-section. Subrectangular in plan, meaning its outline is broadly oblong with slightly irregular edges rather than a precise geometric form, it is a modest specimen by the standards of Irish prehistoric monuments, though its situation on an open hillside slope gives it a quiet presence.

Standing stones of this kind are scattered across the Irish landscape in considerable numbers, and their original purposes remain genuinely uncertain. Some are thought to mark territorial boundaries, trackways, or burial sites; others may have held ritual or astronomical significance for the communities that erected them, likely during the Bronze Age. The stone at Knocknagoun fits this broad, unresolved tradition. What survives is the physical fact of the stone itself, subrectangular, fallen, roughly a metre wide and thirty centimetres thick, lying on a slope where it was presumably once upright and visible from some distance across the valley below.