That appearance is precisely the point. A pond barrow is a prehistoric funerary form defined by its sunken centre rather than a raised mound, the inverse of what most people picture when they think of a Bronze Age burial site. The Clonydonnin example measures seventeen metres across and sits about 0.4 metres below the surrounding ground level, enclosed by a low earthen bank roughly five metres wide, though that bank has deteriorated considerably and now stands only about 0.2 metres above the exterior ground. No entrance gap or causeway is visible in the bank, and some material has been dumped inside the central hollow, obscuring whatever original surface might remain.

The site occupies a gentle rise in the landscape with open views in all directions, a positioning that was rarely accidental in prehistoric monument-building, where prominence and visibility seem to have mattered as much as the burial itself. What makes the Clonydonnin site particularly interesting is its proximity to a bullaun stone located in the same field, roughly seventy metres to the north-east. A bullaun is a large stone, usually a boulder, with one or more cup-shaped depressions ground into its surface; they are found widely across Ireland and are associated variously with early Christian activity, folk ritual, and sometimes much earlier use. The pairing of a possible prehistoric barrow and a bullaun in the same field hints at a landscape that accumulated significance across several different periods, each generation apparently finding the spot worth returning to, for reasons that have not survived alongside the monuments themselves.