Built in the sixteenth century, as evidenced by its gun loops and distinctive stonework, this four-storey limestone fortress tells a tale of defensive architecture from an era when such structures dotted the Irish countryside. The castle’s history is intertwined with local families; by 1654, when the Civil Survey recorded it as ‘a castle all ruined ye walls onely standinge with a little barbicon’, the lands of Borris were divided amongst several landowners including members of the Meara family and Sir Jon Magrath, all noted as ‘Irish Papists’ in the historical record.

The rectangular tower, measuring roughly 6.2 metres north to south and 7.5 metres east to west, showcases classic defensive features despite centuries of decay. Its walls, 1.2 metres thick and built from roughly coursed rubble limestone with a protective base batter, once supported timber floors between each level, with the exception of the ground floor which featured a barrel vault, now partially collapsed. The original entrance in the east wall has been broken out, and whilst the spiral staircase tucked into the southeast corner once provided access to all floors, it now lies in ruins above the first floor. A shadow on the external east wall hints at a former adjoining building, suggesting the tower was once part of a larger complex.

The castle’s internal layout reveals the daily life and defensive priorities of its inhabitants. Gun loops strategically placed throughout the structure, particularly concentrated on the first and second floors, provided defensive positions whilst flat-headed windows, some single and others two-light, allowed natural light into the chambers. Practical amenities included a garderobe chamber on the first floor with its chute exiting just above ground level, a large fireplace on the second floor (though its decorative surrounds have long since vanished), and various cupboards and niches throughout the upper levels. Two small chambers at the eastern end of the second floor, one topped with a barrel vault, likely served as private quarters or storage spaces. About 160 metres to the west lies a moated site, suggesting this area once formed part of a larger medieval settlement pattern typical of Anglo-Norman colonisation in North Tipperary.