This rectangular stone fortress, measuring roughly 14.8 metres east to west and 11.3 metres north to south, likely began life as a modest 13th-century hall-house before undergoing dramatic transformation in the late 16th century. The addition of two upper storeys during this period transformed it into the four-storey tower with gabled attic that we see today, albeit now heavily shrouded in ivy and missing its southeast corner.

The castle’s history is well documented from 1585, when it belonged to one Ullig McReamon Burke, and it remained occupied until 1703. Inside, the ground floor was divided into two vaulted chambers by a later cross-wall, whilst wooden floors above were supported by corbels, some ornately carved in the distinctive style of the late 16th-century Gaelic revival. The remodelling brought modern comforts for its time; multiple fireplaces warmed the upper floors, mullioned windows replaced earlier narrow slits, and a projecting latrine provided necessary facilities. Defensive bartizans once jutted from three corners of the tower, whilst rectangular chimney stacks crowned both the west gable and north wall.

Today, Castle Hacket presents a rather romantic picture of decay. Dense ivy obscures most of the stonework, with only the doorway, some window openings and chimney stacks still clearly visible. Trees have taken root atop the ground-floor vaults, and the two-storey gabled structure that once leaned against the eastern wall has vanished without trace, as has any evidence of the bawn wall that once enclosed the castle grounds. Despite its current state, the castle remains an evocative reminder of how Gaelic lords adapted their medieval strongholds to meet the changing fashions and defensive needs of Tudor Ireland.