In 1839, the Ordnance Survey Letters noted a solitary chimney rising from the ruins of an ancient house in the townland of Kiltown, said to have belonged to the Brennans. The surveyor made a rough drawing of the south gable as it then stood, showing a large fireplace at ground level, broken masonry climbing to first-floor height, and a diagonally set chimney breast still bearing the scars where roof coping stones had once bedded in. It is a peculiar kind of architectural document: a sketch of something already half-gone, preserving details that would soon exist nowhere else.

The house is thought to date to the late sixteenth or early seventeenth century, built for an important branch of the O'Brenan family who held territory in this part of County Kilkenny. Writing in 1905, the historian William Carrigan recorded that their residence stood a little to the east of the local churchyard, in a field known as the Closhawn, and was referred to locally as Brenan's Castle. By Carrigan's time, one gable still stood, reportedly seven feet thick and twenty-five feet high, dimensions that speak to a building of considerable weight and ambition. That gable finally came down around 1880. What Carrigan could still observe were low earthen mounds spreading across the site, suggesting that the main house and its surrounding outbuildings had together covered something close to an acre of ground. For a rural residence of that period, that is a significant footprint, pointing to a household of real regional importance rather than a modest tower house or farmstead.

Today the Closhawn field holds little that announces itself to a casual visitor. The mounds Carrigan described may still faintly pattern the ground, but the chimney recorded in 1839 is long gone, and the gable that outlasted it by forty years has left nothing standing. What remains is largely a matter of topography and documentary record, the outline of a place that was already disappearing when the first careful eyes were turned on it.