A cashel is a type of early medieval ringfort defined by a stone wall rather than an earthen bank, and this one near Kilfenora sits low in the landscape amid scrub, brambles, and uncleared pasture, overlooked from all sides and easy to miss entirely. It was already being swallowed by the land when the Ordnance Survey mapped it in 1840, and again when revised editions were produced in 1916.

The antiquarian Thomas Johnson Westropp visited and recorded it in 1915, describing what he found as a well-built and handsome fort, though not a large one, and noting that it was by then nearly all knocked down. His observation of two concentric rings still holds: the inner cashel wall, subcircular in plan and roughly 27.5 by 28 metres across, is built of limestone blocks with a rubble core, and though much of it has collapsed and been overgrown, the inner and outer facing stones are intermittently visible, with up to four courses still standing at the south-east and south-west, reaching a maximum height of around a metre. A later concentric stone wall encloses the whole structure from outside. Within the interior there is a souterrain, an underground stone-lined passage or chamber typically used for storage or refuge in early medieval Ireland, located west of centre. In the north-west quadrant, a short line of upright limestones running parallel to the wall may be the remnant of an internal structure, though its original function is unclear. Around 88 metres to the west-north-west, a second cashel survives, suggesting this was once a more densely settled corner of the Burren landscape than it might appear today.