But the arrangement is deliberate and its purpose was once a serious matter: this is a mass rock, a makeshift outdoor altar of the kind used by Catholic communities during the Penal era, when the public practice of the faith was suppressed under a series of laws introduced in the late seventeenth and early eighteenth centuries. Priests and congregations gathered in remote or sheltered spots, using a natural or roughly fashioned stone surface in place of a church altar. The slab here, measuring 1.31 metres long and 0.5 metres wide, rests on loosely piled stones and sits beneath a hillside that rises sharply above it, offering both concealment and a natural backdrop.

The setting gives a sense of how carefully these locations were chosen. The site overlooks a mill race, the channel that carried water to power a nearby mill, and sits beside a laneway known locally as Bianconi's road, named after Charles Bianconi, the Italian-born entrepreneur who built a celebrated network of horse-drawn passenger coaches across Ireland in the nineteenth century. His routes became arteries of rural life, and the road's association with his name suggests it was once a well-used thoroughfare. The Harrystown flour mill stands roughly thirty metres to the west, and a small bridge crosses the mill race just eight metres to the north-west. That a place of clandestine worship should occupy the same tight cluster of landscape as a working mill and a busy road speaks to the way communities folded religious practice into the fabric of everyday life, finding what shelter and secrecy they could in plain sight.