The site, located on a southwest-facing slope near a farmhouse in Ballywilliam, appears on historical Ordnance Survey maps from 1839 and 1925 as a rectangular structure measuring approximately 15 metres north to south and 8 metres east to west. Today, however, no visible remains of any building can be found at ground level; only the tree and local memory preserve this curious piece of the landscape’s past.

The castle’s name presents something of a historical puzzle. The Civil Survey of 1654-6, a comprehensive record of land ownership in Ireland, shows no one named Warren owning land in Ballywilliam, nor does it mention any castle in the area. This discrepancy between the mapped structure and the documentary evidence raises intriguing questions about the site’s true nature and origins. Was it perhaps a fortified house rather than a proper castle, or did it belong to an earlier period not covered by the Civil Survey?

Despite the absence of physical remains, the site continues to intrigue local historians and archaeologists. The persistent labelling of the location as Warren’s Castle on multiple editions of Ordnance Survey maps spanning nearly a century suggests that some form of substantial structure once stood here, significant enough to warrant consistent cartographic attention. Whether it was a defensive structure, a grand residence, or something else entirely remains one of those tantalising mysteries that pepper the Irish countryside, where history often lies just beneath the surface, waiting to be rediscovered.