It measures just 0.9 metres high and 1.2 metres wide, and to a passing eye it might read as little more than a displaced boulder. In fact it served as an altar, one of hundreds of mass-rocks scattered across Ireland, where Catholic priests celebrated the Mass in secret during the Penal Laws era, when open practice of the faith carried serious legal penalties and the formal infrastructure of the Church had been largely dismantled.

What gives this particular site an additional layer of interest is what lies a short distance above it. Around six metres further up the cliff face, a natural cave is said to have provided a hiding place for priests during those same penal times. The arrangement makes a quiet kind of sense: the congregation gathered below, the altar stone set against the rock, and a refuge immediately overhead should lookouts signal the approach of authorities. The detail comes from O'Brien, writing in 1970, and gestures at the practical ingenuity that characterised clandestine worship in this period. The landscape of Hungry Hill, rugged and sparsely populated, would have offered both cover and a degree of natural warning against intrusion.