Whilst the first edition six-inch OS map from the mid-19th century shows no religious markings here, the current edition notes an ‘Altar (Site of)’, marking a spot that once served as a Penal Mass station during Ireland’s darkest period of religious suppression.

These outdoor Mass rocks, or altars, were born of necessity during the Penal Laws era, when Catholic worship was forbidden and priests risked execution for celebrating Mass. Hidden in remote glens, on mountainsides, or tucked away in places like Cionn Caslach, these rough stone altars became sacred spaces where communities gathered in secret, often with lookouts posted to warn of approaching authorities. The faithful would travel for miles in the early morning darkness, risking fines, imprisonment, or worse to practise their faith.

The fact that this site appears only on later OS maps speaks to how these locations were preserved in local memory long after the Penal Laws were relaxed in the late 18th and early 19th centuries. Though the physical altar may be gone or reduced to scattered stones, its inclusion on modern maps ensures that this chapter of Irish history, when faith meant defiance and Mass meant rebellion, remains part of the landscape’s documented heritage.