Mass-rocks are among the more quietly charged features of the Irish rural landscape: ordinary stones, often indistinguishable at a glance from the surrounding geology, that were used by Catholic priests to celebrate Mass during the Penal Law era, roughly the late seventeenth and early eighteenth centuries, when public Catholic worship was prohibited under British colonial legislation. Congregations would gather at remote hillsides, in hollows, or behind field boundaries, with lookouts posted against the possibility of discovery. The rock itself was the altar, and the site was chosen for concealment rather than ceremony.

The Penal Laws, which varied in their severity and enforcement across different periods, effectively barred Catholics from practising their faith openly, building churches, or educating their clergy within Ireland. The response, in many rural communities, was to continue worship in the open air at locations known only locally and passed on through memory rather than record. Mass-rocks survive across the country in considerable numbers, particularly in counties like Clare, where the terrain offered natural cover. Many were never formally documented, and their identification today often depends on oral tradition and local knowledge rather than any written source. The one at Annagh remains, for now, a point on the map whose fuller story has yet to be formally set down.