A bullaun is a rounded depression, deliberately hollowed into a rock, whose precise original purpose remains debated; they are associated with early medieval monastic sites, with ritual use, and with the collection of water believed to carry curative or sacred properties. Four of the Brockagh stones sit together in a cluster known as the Seven Fonts, a local name that suggests a long tradition of regarding the basins as sources of blessed water, even if the arithmetic between the name and the actual count of stones does not quite resolve itself.

The setting reinforces the sense that something deliberate brought these stones into significance. The Ordnance Survey six-inch map notes a location some hundred metres to the northwest as the site of a thornbush associated with St Kevin's Keeve, a keeve being an old word for a tub or vessel, again suggesting water-holding as the connective thread. St Kevin is the founding saint of the great monastic city of Glendalough, barely a short distance from Brockagh, and St Kevin's Road is the ancient pilgrimage route that crosses the mountains into the valley. The stones were described by Healy in 1972; one boulder measures roughly 1.1 metres square and 0.7 metres high, with a single basin approximately 0.38 metres across and 0.15 metres deep. Another, positioned in the corner of a neighbouring field, is flat-topped, its basin sitting just 0.12 metres from one edge, giving it an almost deliberate, presented quality.