The bullaun, a rounded depression ground into a boulder or loose rock, is one of the more quietly persistent features of early Irish ecclesiastical and ritual sites. Their exact purpose remains debated, but they appear across Ireland in association with early Christian settlements and ancient boundaries, sometimes used for grinding, sometimes attributed with curative or votive significance. The one at Creevykeel was noted in the record, and then, effectively, lost.

A report compiled by the Office of Public Works in 1942 documented the bullaun as sitting within the interior of the cashel, a type of stone-walled enclosure associated with early medieval settlement and farming in Ireland. That record placed it firmly inside the site. But by the time later investigators came to verify its presence, the cashel had become so densely overgrown with scrub that the stone could not be located. It had not necessarily gone anywhere. It was simply no longer findable, swallowed by vegetation and time. The 1942 report stands as the only confirmed sighting, and the gap between that observation and any subsequent attempt to corroborate it tells a small story about how quickly a landscape can close around something.