It is a rath, the most common type of early medieval enclosure found across Ireland, typically built as a defended farmstead sometime between the sixth and twelfth centuries. What makes this one quietly interesting is precisely how little of it remains, and how much of what does survive has been shaped as much by later agricultural activity as by any original design.

The monument measures approximately thirty metres north to south and twenty-eight metres east to west, making it a fairly modest example of the form. A rath was usually defined by a raised earthen bank, known as a cashel when built in stone, with a ditch, or fosse, dug outside it to provide both the material for the bank and an additional barrier. At Corrspark, the bank has been heavily denuded, reduced to little more than a low swell in the ground, and the external fosse is only legible on the northern side and along a stretch running from the south-east around through south to south-west. Where these features have vanished entirely, a natural or modified scarp in the land takes over the enclosing role. A later field bank, the kind of mundane boundary thrown up by farmers across many centuries, cuts directly across the monument at two points, at the north-north-east and south-west, further complicating any reading of what was originally there.