The site is a ring barrow, a type of prehistoric funerary monument in which a low central mound is encircled by a shallow ditch, known as a fosse, and an outer earthen bank. What makes this particular example quietly arresting is its setting: rushy, waterlogged pasture that rises only slightly above the surrounding flood-prone land, as if the monument were perpetually on the edge of being reclaimed by the lough beside it.

The barrow itself is modest in scale. The central platform measures roughly 3.9 metres north to south and 3.6 metres east to west, rising just 15 to 35 centimetres above the fosse that encircles it. That fosse is narrow, between half a metre and 0.6 metres wide, and beyond it sits an external bank averaging around 1.2 to 1.7 metres in width. The whole structure sits on a slight rise in otherwise flat, wet terrain, with the ground climbing gradually northward for about 150 metres before steepening towards an east-west ridge. A second ring barrow of the same type lies approximately 140 metres to the north, suggesting this corner of Cuillaun was once a place of some significance to the communities who shaped it, though what precise period they belonged to the landscape alone no longer tells.