That name has stuck, though the structure it describes is not an altar in any liturgical sense most people would recognise. It is a leacht, a type of devotional cairn or commemorative stone heap found at early Christian sites across Ireland, typically associated with prayer, pilgrimage, or the veneration of a saint. This one measures roughly two metres along its longer axis and stands just under a metre high, a modest but deliberate accumulation of stones that someone, at some point, considered worth marking on a map.

The cashel in which it stands is a stone-walled enclosure of the kind common in early medieval Ireland, built without mortar and designed to define and protect a settlement or ecclesiastical site. Within that enclosure, the leacht occupies a specific position, and around it there are further hints of what this ground once meant to people. Stone slabs protrude above the turf to the east and south of the mound, and these, according to the archaeologist Dr J. Waddell, may indicate the presence of graves. If so, the "Altar" sits at the centre of a small sacred landscape, layered with the overlapping intentions of the living and the dead, though the precise date of any of it remains uncertain.