That absence is itself part of the story. Mass rocks are the bare limestone or exposed outcrops where Catholic priests celebrated the Eucharist in secret during the Penal Law period, when public Catholic worship was suppressed under English colonial legislation. The congregation would gather outdoors, in remote or naturally sheltered spots, with lookouts posted against the approach of soldiers or informers. The name of this particular hollow, Poulataggart, offers a clue to its past: the Irish "poll an tsagairt" translates roughly as "the priest's hole" or "hollow of the priest," a toponym that recurs across Ireland wherever clergy once had reason to keep out of sight.

The place appears on the 1842 edition of the Ordnance Survey six-inch map as an oval hollow, roughly 45 metres on its longer axis and 30 metres across, sitting at the leading western edge of a terrace on the slope. That it was thought significant enough to name and mark at that scale, even decades after the Penal Laws had been relaxed, suggests the memory of its use had not faded locally. It was also recorded as a Mass Rock on Tim Robinson's 1977 map of the area, by which point it had presumably passed into the settled geography of local knowledge. What the 1997 inspection found, however, was that no physical mass rock, no flat stone or altar feature, could be identified on the ground. Whether it was removed, was never a discrete stone to begin with, or simply defies relocation on a rough and craggy hillside, is not recorded.