That is perhaps the most telling detail about this site: what survives of the enclosure is so eroded that its eastern side has vanished entirely into the ground, leaving a roughly subrectangular outline, around 31 metres east to west and 30 metres north to south, defined only by a denuded bank. The water filling the interior is not incidental. It is, in a quiet way, the most visible thing left.

Enclosures of this general type, roughly circular or subrectangular earthworks defined by a bank and sometimes a ditch, are among the most common archaeological features in the Irish landscape, and among the least understood. They may have served as farmsteads, as places to secure livestock, or as boundaries with social and ceremonial meaning. Without excavation it is rarely possible to say more. At Knockroe, the bank has been so worn down over centuries of agricultural activity that the site registers more as an absence than a presence, its shape legible mainly on paper rather than underfoot.