The earthen enclosure at Kilcoolaght, known locally as Lismore or Lios Mór, belongs firmly to the second category. A rath is a type of ringfort, a circular earthwork enclosure typically dating from early medieval Ireland and used as a farmstead or place of habitation. This one was levelled around 1970, and what little remained afterwards became densely overgrown, leaving it in a poor state of preservation by the time anyone thought to record it carefully.

Situated north of Macgillycuddy's Reeks and east of the Cottoners river, the site occupies a geographically distinctive position in south Kerry, tucked into the landscape of the Iveragh Peninsula. It appears on both editions of the Ordnance Survey maps, which places it within the documentary record even as the physical fabric was disappearing. The name Lios Mór, meaning something like "great enclosure" in Irish, hints at a site that may once have been substantial, though little now survives to confirm that. The levelling in 1970 was likely agricultural, a common fate for ringforts across Ireland during the decades following mid-century land improvement schemes, when earthworks that had endured for over a thousand years were cleared in a matter of days.