Known as Bullaun 3, it measures just 52 by 42 centimetres across and 33 centimetres deep, the kind of stone you might step over without a second thought. But set into one end is a carefully formed bowl-shaped basin, and beside it sit two drilled holes whose purpose nobody has been able to satisfactorily explain.

Bullaun stones are found across Ireland, typically associated with early ecclesiastical sites, and their basins are thought to have held water used in ritual or healing contexts. This example fits that general pattern well enough: the basin, roughly 26 by 25 centimetres across and 12 centimetres deep, is a convincing specimen of the type. What sets this stone apart are the two small holes drilled 4 centimetres to one side of the basin, measuring roughly 3 centimetres across and between 2.5 and 4 centimetres deep. Their dimensions closely resemble the holes quarry workers would drill when preparing a large boulder for blasting, a technique in which explosive material or metal wedges were inserted to split the rock along a controlled line. The difficulty is that this boulder is far too small to have warranted such treatment, and there is no suggestion it was ever part of a larger mass that needed breaking apart. Alongside the drilled holes, there is also a shallow cup mark, just 3.5 centimetres across and half a centimetre deep, of the kind found on prehistoric stones throughout Ireland and Britain, though what relationship it bears to the bullaun basin or the drilled holes is equally unclear. The stone thus presents three distinct features, each legible in isolation, but together forming a combination that does not resolve neatly into any single known tradition or use.