The site's Irish name, Lios Abhann Rua, translates loosely as the fort of the red river, and the Owroe itself once formed part of the site's eastern defences. What the first edition of the Ordnance Survey map recorded was a bivallate enclosure, meaning one with two concentric banks, a more elaborate arrangement suggesting a degree of status or deliberate fortification. By the time the second edition was drawn, only a single bank remained legible in the landscape. Whether the outer bank was robbed for field walls, silted away, or was always less substantial than the cartographer assumed is not recorded.

Ringforts, known in Irish as raths or lios, were the most common form of rural settlement in early medieval Ireland, typically enclosing a farmstead and its associated buildings within an earthen bank and ditch. This one sits roughly 30 metres west of the Owroe today, its bank standing 1.3 metres high on the outside and just under a metre on the interior face, with a basal width of nearly five metres. Those are solid, if not exceptional, dimensions. What makes Knockroe more curious than most is what occupies the interior: a large stony mound, some 13 metres across, overgrown and without any visible stone facing. The working interpretation, offered by archaeologists Aidan O'Sullivan and Jerry Sheehan in their 1996 survey of South Kerry, is that it may represent the collapsed remnants of a substantial hut structure. Without excavation, that remains a reasonable inference rather than a confirmed fact, and the mound sits there quietly, its original form long since obscured by vegetation and time.