Where the enclosure meets a steep ravine carrying the Aille River northward, the earthwork dissolves into an overgrown, intermittent ridge, as though the builders decided the natural drop into the gorge was defence enough. It is one of those small details that rewards a careful look at an otherwise unremarkable-seeming field monument in the hilly pastureland of County Clare.

The site is a rath, the Irish term for an earthen ringfort, a class of monument built predominantly in the early medieval period and used as an enclosed farmstead by people of varying social rank. This particular example is suboval in plan, measuring roughly 25 metres north-northwest to south-southeast and about 21.5 metres across the perpendicular axis. It sits at the top of a rise with wide views across the surrounding landscape, the land to the west-southwest dropping sharply into the ravine below. A round-topped earthen bank, between 2.2 and 3.3 metres wide and standing up to about 1.2 metres on its outer face, defines the circuit on the better-preserved eastern side, accompanied by a flat-based external fosse, essentially a ditch, roughly 1.5 metres wide and 1 metre deep. The fosse disappears entirely along the ravine edge, and to the north there is only a berm of raised ground where it may once have been levelled. The fort had already been mapped and named by 1842, appearing on the first Ordnance Survey six-inch sheets, and again on the 1920 revision, labelled each time as Aughnavinna Fort. Three cattle gaps have since been cut through the bank, and recent topsoil removal has caused some further disturbance. A wire fence now crosses the southern part of the fosse. A faint causeway beside the easternmost gap hints at where an original entrance may have been.