A cashel is a type of early medieval ringfort built from stone rather than earth, and this one measures roughly 66 metres north to south and 62 metres east to west, placing it well above the typical scale for such structures. Much of the wall has tumbled and is partly grass-covered, but it can be traced for its entire circuit, and on the eastern side both the inner and outer facing-stones are still visible, showing a wall nearly two and a half metres wide. Most striking is the entrance on the south-south-east side, stone-lined and splaying outward in the manner that builders used to ease the passage of people and animals alike, its outer face nearly two metres wider than its inner. The antiquarian Thomas Westropp, writing in 1915, was struck enough by the place to single it out for its unusually large battered walls, meaning walls built with a deliberate inward lean for structural stability, rising to between six and seven feet and composed of large, well-fitted blocks.

What makes this site particularly layered is the evidence it preserves for long and repeated human use of the valley. Inside the cashel, south of centre, lie the remains of two stone buildings and a midden, the accumulated domestic refuse that can signal sustained occupation over generations. A field system of at least three distinct phases crosses the interior and extends outward in all directions, suggesting that the landscape around the cashel was organised and reorganised repeatedly over time. Researcher Paul Gosling identified these phases in 1991, and the pattern is reinforced by a second enclosure with its own associated field system located roughly 450 metres to the west-south-west, on the opposite side of the valley. Crucially, both sets of field remains stop just short of the improved strip fields that now run down the valley floor, visible in aerial photographs taken by Cambridge University in 1970. The implication is that the older field systems once continued across the whole valley but were erased where the land was brought into more intensive modern use.

A path running north from the cashel climbs the saddle between the two hills and descends toward the Burren coast, so the enclosure sits at a natural junction between the valley's pastureland and the wider landscape beyond. The entrance on the south-south-east and the well-preserved facing-stones on the eastern wall are the clearest structural details to look for once on the ground, as much of the rest of the circuit survives only as a low, grassy spread rather than upstanding masonry.