At Coollick in County Kerry, a rath sits on a steep south-west-facing slope at the very edge of a deep ravine, and its builders appear to have treated that natural drop as a structural asset rather than a hazard. The earthen banks on the south-east side do not continue around to complete a full circuit; instead, they terminate abruptly at the ravine's lip, letting the sheer ground do the work. A stream adds another layer of peculiarity: it enters the fosse, the ditch between the banks, from the north-north-west, flows along the base of it, and then exits southward over the edge of the ravine. The interior, despite all this drama around its edges, is level.

A rath is a ringfort defined by earthen banks and ditches rather than stone walls, and this one is more elaborate than most. It measures roughly 31.5 metres east to west and retains two earthen banks with an intervening fosse, along with the remains of what may be a third bank to the east-south-east. The middle bank is the most substantial, rising to an external height of over three metres in places. Stone-facing survives on both banks at either side of what appears to be a causeway entrance on the eastern side, wide enough for a person to pass through. Two possible hut sites have been identified inside the enclosure, in the south-west and south-east quadrants, and the stump or base of a standing stone sits in that south-east interior as well. The fort is not alone in the landscape: another rath lies roughly sixty metres to the south, on the far side of the same ravine. When members of the County Kerry Field Club visited in the 1940s, they recorded it as "the great fort on Fleming's land at Coolick," noting its "high commanding position" and "very high ramparts and moat," language that suggests the earthworks were already impressing observers long before any formal survey took place.