A low, grass-smothered stony bank, nowhere taller than about forty centimetres and no wider than two metres, traces a rough circle across rough grazing land on the Burren. The interior, some seventeen and a half metres across, is flat and offers nothing obvious to the eye. There is no visible entrance, no upstanding stonework, and the structure has subsided so gradually into the landscape that it is easy to read it simply as a natural undulation. A cashel, the term used for a stone-walled ringfort as distinct from the more common earthen equivalent, would once have enclosed a farmstead or small settlement, its wall a statement of ownership and protection rather than a military fortification. This one has all but returned to the hillside.

What makes the site worth attention is less the monument itself than the company it keeps. Writing in 1897, the antiquarian W. C. Borlase counted twenty ringforts between Derreen West and East alone, and thirty-three across the slope as a whole, including the north-west facing side of Knockauns Mountain. That density is genuinely unusual, even by the standards of the Burren, a limestone landscape already remarkable for its concentration of early medieval remains. T. J. Westropp, visiting a few years later and recording his findings in 1901, noted that several of the forts had been largely levelled and reassembled as sheep folds, though he remained confident of their ancient origin. The low banks running away from the cashel to the south-east and south-west may represent the ghost of a field system contemporary with the fort itself, suggesting the surrounding land was managed and divided during the same period of occupation. A more recent square enclosure of drystone walling sits about ten metres to the west, and a doline, a natural depression characteristic of karst limestone, lies roughly twenty-five metres to the north. The site appears on Ordnance Survey six-inch maps from 1842 and again from 1915, each time marked with hachures indicating an earthwork, which means its outline was legible to surveyors even then, despite the slow erasure already underway.