The bullaun stone at Derryrush, a natural or artificially worked hollow ground into bedrock, sits under the tarred surface on the northern side of the Lehid-Kilmakilloge road, on a south-west-facing slope of rough, gorse-covered pasture. Bullaun stones are among the more quietly persistent features of the Irish landscape, basin-shaped depressions in rock that are found near early ecclesiastical sites, field boundaries, and roadsides, and which have long attracted folk belief around healing and water. This one, though, is doubly obscured: first by the road that was laid over it, and then by the decades that have passed since anyone could see it at all.

Before the road was tarred, local people knew the bowl-shaped hollow well. It was, they said, always filled with water, and was regarded as a holy well, the kind of modest, informal sacred site that once dotted the Irish countryside in great numbers, often with no formal dedication or institutional backing, just a persistent local understanding that the water held some significance. The act of road-building erased the visible trace, though not the memory. About ten metres to the south-east, on the opposite side of the road, a mass-rock survives above ground. Mass-rocks are flat-topped boulders or outcrops where Catholic priests celebrated Mass in secret during the Penal period, roughly the late seventeenth and eighteenth centuries, when public Catholic worship was suppressed under law. The proximity of the two features, the submerged bullaun with its association with sacred water and the exposed mass-rock just across the road, suggests this quiet hillside in south-west Kerry was once a place of some local religious significance, even if nothing of it now announces itself to a passing driver.