It stands up to 4.5 metres at its highest point, and on its southern face a natural shelf, roughly 1.3 metres above the ground, projects outward in a way that has earned it the name "pulpit" among local people. The northern face, by contrast, is sheer and perpendicular. What makes this unremarkable-looking feature quietly significant is the name it has carried for generations: a mass-rock.

Mass-rocks are closely associated with the Penal Laws, a body of legislation that, from the late seventeenth century onwards, severely restricted Catholic worship in Ireland. With Catholic churches suppressed or denied to priests, congregations gathered outdoors at remote or discreet locations, where a flat rock would serve as an improvised altar. The arrangement here, with its raised shelf on the south face acting as a kind of natural lectern or altar surface, is a good example of how the landscape itself was pressed into liturgical use. The rock at Ardura Beg retains its local designation, passed down through oral tradition, long after the conditions that gave rise to it have disappeared.