A rath, broadly speaking, is a circular earthwork enclosure, typically of early medieval date, defined by one or more earthen banks and used as a farmstead or high-status residence. The interior of such enclosures is often level and open, the activity of centuries having long since been flattened or absorbed into the soil. At Knockroe, however, a large stony mound dominates part of that level interior, overgrown now and shapeless, measuring roughly thirteen metres across. Nothing about its surface announces what it is or was.

The mound may be the collapsed remains of a substantial hut once built within the rath. No stone facing survives, or none that is currently visible, which makes a confident identification impossible. What can be said is that the scale of the mound, thirteen metres in diameter, suggests something more considerable than a minor outbuilding. Structures of this kind within raths are not uncommon across Ireland, but the combination of size and the degree to which this one has subsided into an undifferentiated heap gives it a particular quality of ambiguity. The site was documented by A. O'Sullivan and J. Sheehan in their archaeological survey of the Iveragh Peninsula, published by Cork University Press in 1996, which remains one of the most thorough regional surveys of its kind in the country.