According to historian O’Leary’s late 19th-century research, a date stone bearing the code KD003-017001 confirms that John Lye, a local gentleman, built a castle here in 1578. However, this wasn’t simply a case of developing vacant land; the construction came at the expense of existing religious structures.

The area had previously housed a religious establishment, complete with a burial ground and stone cross, but Lye had other plans for the site. A 1608 Inquisition held at Naas revealed the full extent of his actions: “John Lye of Rathbride, gent., being seized of divers lands in the said townland of Clonaugh, levelled the tenements, bounds, and limits of said religious house, threw down and destroyed the cross and trees and erected a tower, or small castle, with other buildings.” This deliberate destruction of religious property to make way for a private fortification reflects the turbulent religious and political changes of 16th-century Ireland.

The castle itself has long since vanished from the landscape, with no visible traces remaining by 1985 according to archaeological surveys. Its stones found new life elsewhere; O’Leary notes they were repurposed to build Kilshanchoe Church in the early 20th century. Today, only scattered fragments hint at the castle’s existence: two armorial plaques now grace the walls of a primary school in nearby Johnstown village, whilst an architectural fragment has been incorporated into a modern wall in the same village, serving as tangible links to this contentious piece of local history.