The earthwork they have colonised is a rath, a type of circular enclosure built from a raised bank of earth and sometimes an outer ditch, which served as the dwelling and farmyard of a single farming family, likely somewhere between the fifth and twelfth centuries. Thousands of them survive across Ireland in varying states of preservation, but this particular example in Ballyhehan has been reduced to something more ghostly than most.

Only an arc of the original bank remains, running from the north-east to the south-east of the circuit, stretching 35 metres in length and measuring just over seven metres wide at its base. The interior face rises only half a metre, the exterior face a little over a metre. The rest of the enclosure has been lost to centuries of agricultural improvement, and the surrounding land is now cleared pasture. Despite this, the knoll itself retains a quality that would have made it attractive to its original builders: the ground falls away moderately steeply on all sides, giving open views across the landscape in every direction. That combination of elevated ground and good sightlines was a consistent preference among those who chose where to build these enclosures. The rath appeared on both the 1842 and 1915 editions of the Ordnance Survey six-inch maps, marked with the hachure symbol that cartographers used to indicate earthworks, and it was subsequently recorded in official heritage inventories in 1992 and 1996, where it was cautiously catalogued under the broader category of enclosure rather than assigned the more specific designation of rath.