It was built from limestone and mortar, stood nearly three metres high, had walls roughly sixty centimetres thick, and one side had already begun to crumble. By the time anyone looked again, nothing remained of it. What the surveyor most likely encountered was a lime kiln, one of the small stone furnaces once used across rural Ireland to burn limestone and produce agricultural lime, and the 1842 Ordnance Survey six-inch map shows exactly such a structure abutting the northeastern edge of the earthwork. It is a small, easy-to-miss collision of eras: a prehistoric monument repurposed as a convenient wall for a post-medieval industrial feature, the one outlasting the other by a considerable margin.

The earthwork itself is a rath, the Irish term for a ringfort, a type of enclosed farmstead built predominantly during the early medieval period, roughly between the fifth and twelfth centuries. This example consists of two concentric earthen banks separated by a fosse, which is simply a ditch dug to reinforce the defensive or enclosing effect of the banks. The inner bank runs to about six metres wide and stands up to three metres on its outer face, though it is poorly preserved in places, with gaps appearing along its northern arc. The outer bank is considerably slighter and, on its northern and western sides, barely traceable at all. A causeway entrance survives at the south, facing out over the valley. The whole enclosure measures roughly twenty-nine metres north to south and twenty-eight metres east to west, with a level interior and trees now growing along both banks. It sits on a south-west-facing slope, which would have given whoever lived here an unobstructed view down to the Roughty River.