The 1839 Ordnance Survey six-inch map depicts what appears to have been a rectangular structure, most likely a tower house; a type of fortified residence favoured by the Irish gentry from the 15th to 17th centuries. Today, no physical trace of the building remains above ground, leaving historians and archaeologists to piece together its story from documentary evidence alone.

The site’s identification as a probable tower house places it within a broader pattern of defensive architecture that dotted the Carlow landscape during the late medieval and early modern periods. These structures typically featured thick stone walls, narrow windows, and multiple storeys accessed by spiral staircases, serving as both home and fortress for local landholding families. The rectangular footprint shown on the 19th-century map supports this interpretation, as tower houses were generally built on a simple rectangular plan with walls up to two metres thick.

The connection between this site and another castle reference in the area (catalogued as CW007-030) suggests Graigue may have been part of a larger defensive network or estate complex. Such arrangements were common in medieval Ireland, where principal castles often had associated smaller fortifications or earlier structures nearby. The complete disappearance of the structure likely occurred sometime between the 1839 survey and the modern archaeological inventory conducted in 1993, though whether it fell victim to deliberate demolition, stone robbing for local building projects, or simple decay remains unknown.