The castle remains stand within a rectangular bawn, or fortified enclosure, with a second structure of the same name located less than a kilometre to the south. When the Ordnance Survey documented the site in the 19th century, they found little more than three metres of the south wall still standing, with the original dimensions of the castle already lost to time. The nearby Donaghmore church lies about a kilometre to the north, placing this castle at the heart of what was once a thriving medieval settlement.

The castle's documented history reveals a succession of owners typical of Irish tower houses during the turbulent 16th and 17th centuries. In 1584, Donnell Mac Canna held the lands, and three years later he entailed the castle to his sons. By 1621, the castle had already fallen to ruin when it was granted to H. Holcroft, described as the former estate of Edmund McCany. The McCanny family appear to have retained some connection to the property, as livery on Drombanny was granted to Edmund McCanny in 1629 following his father Donough's death. Pierce Creagh, son of Andrew and listed as an 'Irish papist' in contemporary records, held the broken castle by 1655, before it was eventually granted to the Duke of York in 1669.

The Down Survey maps from the 1650s provide valuable visual evidence of both Drombanny castles; the Donaghmore site is depicted as a tower house type castle, whilst its southern namesake in the townland of Brownestone appears as a house rather than a fortification. The survey's terrier notes that the Drombanny lands contained not just the ruined castle but also an orchard, suggesting that despite the castle's dilapidated state, the surrounding lands remained productive and valuable enough to merit detailed documentation during this comprehensive mapping project of Ireland.