Today, only the southern portion of the southwest tower survives from what was originally a more substantial fortification featuring two flanking towers that stood at the corners of Castle Cosby house’s yard. The remaining structure, built from roughly coursed limestone masonry with an internal diameter of approximately 2.2 metres, stands as a solitary witness to centuries of change and decay.

The castle’s history remains somewhat elusive; notably, it doesn’t appear on the Down Survey maps of 1656-8 for Kilmore parish, despite local tradition placing a castle at nearby Cavatt. This absence from one of Ireland’s most comprehensive 17th century land surveys raises intriguing questions about the structure’s significance and ownership during the Cromwellian period. The site’s connection to the later Castle Cosby house suggests a continuity of occupation, though the exact relationship between the medieval tower and the subsequent dwelling remains unclear.

Adding to the site’s medieval character, a late medieval stone head has been preserved in a modern dwelling house nearby, catalogued separately in archaeological records. This carved fragment, along with the tower ruins, represents the tangible links to a time when such fortified structures dotted the Cavan landscape, serving as both defensive strongholds and symbols of authority in an often contested borderland region.