The one at Lios Deargáin, in the low country around Trabeg on the Dingle Peninsula, is more ambiguous. Its enclosing bank has been absorbed into the working fabric of the fields around it, pressed into service as an ordinary field fence, and parts of it may have been substantially rebuilt or replaced over the centuries. What survives is irregular in outline and composite in construction, combining earthen bank, earthen bank with stone revetment on one face or the other, and stone walling packed with an earthen core. No clearly-defined entrance survives. The bank reaches a maximum of 1.35 metres on the outside and 1.15 metres on the inside, but in the south-south-east sector it barely clears the interior at all, rising only ten to twenty centimetres above the ground within.

A rath, in Irish archaeological terms, is a ringfort defined primarily by earthen rather than stone construction, typically dating from the early medieval period, roughly the fifth to the twelfth centuries, and understood as an enclosed farmstead or high-status residence. The one at Lios Deargáin sits on level ground at the inner edge of the broad valley surrounding Trabeg, and its internal diameter of 24.4 metres places it within the normal range for a univallate rath, that is, one enclosed by a single bank and ditch rather than multiple concentric rings. It originally lay at the junction of four fields, though one of those boundaries has since disappeared. The site was recorded in the 1986 Corca Dhuibhne archaeological survey of the Dingle Peninsula compiled by J. Cuppage, a systematic catalogue that documented the remarkable density of prehistoric and early medieval remains across this part of County Kerry.