Brookhill House is gone, surviving not even to ground level, yet the stones around its vanished walls carry the traces of something much older, and nobody can quite agree on what that something was.

The confusion begins with the maps. The first Ordnance Survey six-inch edition of 1839 marks the spot as a monastery, though without pinning down the exact location. By the 1900 revision, the cartographers had settled on the more cautious label of "Monastery (Site of)", indicated with a cross. The historian Carrigan, writing in 1905, identified this as the Abbey of Killenny, a daughter house of Jerpoint Abbey, one of the great Cistercian foundations of medieval Ireland. He placed its establishment somewhere between 1162 and 1166, in what was then known as the townland of Old Abbey, now called Barrowmount. But the author of the Ordnance Survey Letters in 1839 was sceptical. His view was that there had been no monastery here at all, but rather a castle, subsequently pulled apart to furnish building material for Brookhill House. That kind of architectural cannibalism was common practice in rural Ireland, where a convenient ruin could supply ready-cut stone for a new project. The irony in this case is that Brookhill House was itself already in ruins by 1839, within what may have been a generation or two of its construction. A field inspection carried out in 1994 found large granite blocks and cut-stone fragments surviving in the outbuildings and surrounding walls. These fragments appear to have come from a medieval structure, but whether that structure was a monastic building, a castle, or something else entirely remains unresolved.