That curve is one of the more telling details about this site. The mound measures roughly ten metres by five and a half, its eye-shaped outline revetted, or faced, with dry-stone walling up to a metre high. Built into its south-eastern edge is a small stone seat, just under half a metre in each dimension, known locally as St Patrick's Chair. A modern statue of the saint stands in a concrete shelter about eight metres away. The whole arrangement is classified as a penitential station, a type of site where people would traditionally carry out acts of devotion or penance, often walking a prescribed circuit, praying at specific points.

The chair and the mound attracted their own tradition, recorded in the Estate Records of William Meade Smythe. According to that account, St Patrick, travelling toward Uisneach, the ancient ceremonial hill roughly nearby, rested at the summit of this hill and seated himself in the chair. People would come and sit in it to obtain a cure for back pain or injury. The same source mentions that a cross once stood beside the chair, though only a portion of it was seen by a man who was already long dead by the time the account was written down. The site's deeper history is harder to fix. When David McGuinness surveyed and described it in 2014, he noted that while the mound cannot be confidently identified as a prehistoric burial mound on the basis of its current appearance, it sits close to the summit of a prominent hill, roughly a kilometre north-west of a confirmed mound-barrow or cairn. The stone revetment is possibly ancient. The simplest reading of the site is that something much older was gradually absorbed into Christian pilgrimage practice, shaped and reshaped by devotion over centuries until the original form became difficult to recover.

The steps built into the roadside wall on the south-south-east side give public access to the mound. The site overlooks Kilmacnevan Church and its graveyard, about 550 metres to the west, and there is a similar rough stone chair associated with a mass-rock in Rathduff townland about a kilometre to the south, suggesting a broader local pattern of such devotional furniture in the landscape.