The hollow itself is modest, the kind of feature you might walk past without a second glance, yet local memory has long identified it as a place where Mass was celebrated in secret, most likely during the Penal Law era when Catholic worship was suppressed under legislation that made the public practice of the faith illegal and potentially dangerous.

Mass-rocks, as they are collectively known, are found across Ireland, typically in remote or elevated spots chosen precisely because they were difficult to approach undetected. A flat stone or natural rock surface would serve as an improvised altar, with a lookout posted nearby to warn of approaching authorities. The hollow at Knockaphonery fits this pattern well: a hilltop position, a naturally formed surface in the rock, and a sustained local tradition that kept the memory of its use alive long after the immediate threat had passed. That tradition, passed down orally through the community, is often the only evidence connecting a particular stone or hollow to its clandestine liturgical past.