At Rossdarragh, what was once possibly a castle now exists merely as a reference on old maps and in the careful notes of antiquarian scholars. The 1654-7 Down Survey Map, housed in the National Library of Ireland, depicts a ruined castle here alongside some cabins, providing a rare glimpse into what this location looked like in the mid-17th century.

The site caught the attention of William Carrigan, the renowned historian who documented Laois's ecclesiastical heritage in his comprehensive 1905 work. Carrigan noted that whilst the Ordnance Survey map marked the location of a Roman Catholic chapel nearby, the castle itself had already vanished from the visible landscape by his time. He described finding a large stone-walled enclosure about two to three hundred yards west of the chapel site, which he believed marked where the old building, perhaps the castle, once stood.

Today, no surface remains are visible at Rossdarragh to confirm the castle's exact location or appearance. The site represents one of countless Irish fortifications that have disappeared over the centuries, victims of time, weather, and the recycling of building materials by local communities. What remains is the archaeological record; the careful documentation by surveyors, historians, and archaeologists who piece together Ireland's medieval landscape from maps, written accounts, and the subtle marks left on the land itself.