This is a rath, the most common type of early medieval enclosure in Ireland, typically consisting of an earthen bank, a ditch, and sometimes multiple concentric rings of both. What survives here is fragmentary but coherent: two banks with an intervening fosse, the ditch between them, enclosing a roughly circular area of around forty metres in diameter.

The survival is uneven. The inner bank can still be traced from the north-west around to the north, but elsewhere it has given way to a simple scarp, a slope rather than a built-up bank, running from the north around through the east and down to the south-west. A later field boundary, the kind of utilitarian stone or earthen division that farmers have been constructing and reconstructing across this landscape for centuries, has been laid directly on top of the rath from the south-west back around to the north-west, quietly cannibalising the older structure. The outer bank and fosse are better preserved on the south-east to south-west arc. A cashel, a stone-built ringfort rather than an earthen one, sits roughly four hundred metres to the south-east, suggesting that this part of Creggaun was a meaningful place for early settlement, with different builders or different generations choosing slightly different approaches to enclosure within the same stretch of ground.