What was once a circular enclosure, a univallate rath (a single-banked earthwork enclosure, typically of early medieval date and associated with a farmstead or dwelling), has lost most of its western half to repeated flooding. The river did not destroy the site dramatically or all at once; it simply took it, over time, leaving the remaining earthwork as a kind of interrupted arc on the landscape.

The site, known locally as Lisduff or An Lios Dubh, sits within the townland of Baile An Phléamannaigh on the Dingle Peninsula. Within the rath's interior, a smaller oval structure was once clear enough to be recorded on the second edition of the Ordnance Survey map, suggesting it served as a hut or subsidiary shelter associated with the enclosure. That structure has since deteriorated into a low oval spread of collapsed material, measuring roughly 5.8 metres by 4 metres, pressing against the inner edge of the surviving bank at the south-east. The details come from J. Cuppage's 1986 archaeological survey of the Corca Dhuibhne region, which remains one of the foundational references for understanding the dense and varied archaeology of the Dingle Peninsula.

What makes the site quietly affecting is precisely what it lacks. The river has done its work thoroughly enough that a visitor standing at the eastern bank would see only a partial earthwork and a shapeless scatter of stone, with no obvious indication of the original circular plan. The absence is, in its own way, the story.