They are known collectively as Roilig Mhuire, and what makes them quietly remarkable is the way they are still being built, incrementally, by the people who pass them. The outer layer of each mound is composed almost entirely of loose small stones deposited by pilgrims over generations, so the cairns are less fixed monuments than accumulated gestures, perpetually unfinished.

The three cairns form part of the Turas, the traditional pilgrimage circuit on Croagh Patrick, Mayo's distinctive conical peak long associated with St Patrick. A turas is a penitential route, a prescribed series of stations at which prayers are said and physical acts, often walking barefoot or circling a monument a set number of times, are performed. Roilig Mhuire is one such penitential station within that circuit, enclosed within a defined boundary on the hillside. The largest of the three cairns measures roughly six metres across and stands about 1.7 metres high. The other two are positioned just three metres and ten metres to its south-west, close enough that the group reads as a single devotional complex rather than isolated features. The loose spread of stones around the base of each cairn is thought to be partly the result of slippage down the slope and partly the ongoing effect of pilgrim activity, the same hands that add stones occasionally dislodging others.