The nineteenth century Ordnance Survey Letters, compiled by O’Flanagan in 1933, reference this elusive structure, noting that whilst the Down Survey indicated a castle existed in Stonestown, no trace of such a building could be found by 1838. This discrepancy between historical documentation and physical evidence has intrigued local historians for generations.

The Down Survey, conducted between 1654 and 1657, provides perhaps the most tantalising evidence of Stonestown Castle’s existence. The barony map of Garrycastle from this period shows what appears to be a keep or tower in Stonestown, preserved in manuscript 716 at the National Library of Ireland. This seventeenth century survey, commissioned by the Commonwealth government to map forfeited lands, offers a rare glimpse into the landscape of post Cromwellian Ireland and suggests that a defensive structure of some significance once stood here.

Today, visitors to the site will find little more than foundation remnants, a subtle reminder of Ireland’s layered history where castles could vanish almost entirely within two centuries. The Archaeological Inventory of County Offaly, published in 1997 by the Stationery Office in Dublin, officially catalogued these remains, though ongoing research continues to shed new light on this mysterious fortification. Whether the castle fell victim to deliberate destruction, gradual decay, or was perhaps cannibalised for building materials by local residents, its story remains largely untold, preserved only in maps, letters, and the faint outlines of stones beneath the Offaly soil.