The castle’s interior measures 32 feet 4 inches by 25 feet, with its main doorway positioned in the north wall at ground level. Inside, three arches built into the eastern wall once supported a defensive walkway and parapet, allowing defenders to patrol and protect the structure. While there are traces of a low vault or arch on the north wall, the building shows no clear evidence of full vaulting; instead, both the north and south walls were constructed as gables.

This MacTibbot Bourke castle remained inhabited well into the nineteenth century, demonstrating the longevity of these medieval structures as family homes long after their military significance had faded. The building’s practical design and solid construction allowed it to serve multiple generations before eventually being converted into Cushlough House, showing how these ancient fortifications were often reimagined for more comfortable domestic use rather than being abandoned entirely.

The castle represents a typical example of the tower houses that dot the Irish landscape, particularly around the shores of Lough Mask. These structures served as both defensive positions and status symbols for local Gaelic and Anglo-Norman families, combining the practical needs of security with the desire to display wealth and power. Today, Cuslough Castle stands as a reminder of how Ireland’s medieval heritage has been continuously adapted and reused throughout the centuries.