Whilst the structure appears clearly marked on the Down Survey map of Rathconnell parish, drawn up between 1655 and 1659, its physical location has never been definitively established. This survey, commissioned by Oliver Cromwell to map confiscated lands following the English Civil War, provides one of the few historical references to the castle’s existence. The original map can be found in the National Library of Ireland’s manuscript collection.

What makes Moygullin Castle particularly intriguing is its complete absence from all Ordnance Survey six-inch maps, which were meticulously compiled throughout the 19th and 20th centuries. These detailed surveys typically recorded even the smallest ruins and archaeological features across Ireland, making the omission of Moygullin Castle all the more puzzling. It’s possible the structure had already fallen into complete ruin by the time the Ordnance Survey began their work, or perhaps it was demolished and its stones repurposed for other buildings in the area.

Located somewhere in the vicinity of Cooksborough in County Westmeath, the castle was likely one of many fortified houses built during the medieval period when such structures dotted the Irish midlands. The research into Moygullin Castle’s location continues, with this particular mystery compiled by historian Caimin O’Brien in October 2016. For those interested in Ireland’s lost castles, Moygullin represents one of many tantalising gaps in our understanding of the country’s built heritage; a structure important enough to warrant inclusion on a major 17th-century survey, yet elusive enough to have vanished almost entirely from the historical record.