Known locally as Lisheen, from the Irish An Lisín meaning the little ringfort, it occupies the southern edge of a headland that looks out towards Illaunamuck, Oileán na muc, the island of the pigs. A promontory fort uses the natural geography of a headland or cliff edge as its main defence, adding a bank and fosse, the ditch dug to reinforce the barrier, across the neck of land to close off the landward approach. Here, both the bank and the fosse curve convex towards the interior, which is an unusual arrangement that gives the enclosing line a bowed rather than straight profile when viewed from the land side.

The stone wall that forms the main defence revets, or faces, a natural rock-scarp, running 34 metres in length and standing up to 2 metres above the fosse. That ditch measures roughly 37 metres across and about 5 metres wide, cut to 0.8 metres below the level of the enclosing field bank. Inside the enclosure, the remains of several structures survive in varying states of preservation. Pressed against the inner face of the stone bank at the north-east end is a sub-rectangular house-site measuring 5 by 10 metres, with walls approximately 1 metre thick. A short distance behind it are two smaller huts, or possibly a single house-site divided in two, one measuring 4 by 6 metres and another 3 by 5 metres. A circular hut site of just 3 metres in diameter occupies the north-west sector, and there are traces of what may be a souterrain, an underground stone-lined passage typically used for storage or concealment. A further rectangular house-site of 5 by 12 metres lies in the south-west. The antiquarian T. J. Westropp, writing in 1909, noted that stones from the house-sites had been reused to wall in the headland, which helps explain the slightly ambiguous state of the structures today, their fabric redistributed across the site in the manner so common to working coastal landscapes.