This three-storey stronghold forms part of a larger defensive complex known as a bawn, a fortified courtyard typical of 17th-century Irish architecture. The bawn’s interior measures 28 metres east to west and 19 metres north to south, though its western wall has long since vanished. What remains tells a compelling story of frontier defence in early modern Ireland.

The surviving walls reveal sophisticated military planning for their time. The northern and eastern walls stand remarkably intact at heights of 3 to 3.5 metres and a thickness of one metre, each pierced with six gun-loops that allowed defenders to fire upon attackers whilst remaining protected. Interestingly, there’s no evidence of a wall-walk or parapet along these walls, suggesting the defenders relied entirely on the gun-loops for their defence. At the northwest corner, the foundations of a circular tower remain visible, measuring 3.9 metres in internal diameter and accessible directly from the bawn courtyard, with one gun-loop still evident in its structure.

The southern wall contains remnants of what was once the main gatehouse, complete with its own gun-loop for defence. About 115 metres south-southwest of the complex lies what may be an earlier motte, suggesting this strategic location overlooking Lough Arrow has been defended for centuries. The Mac Dermot Roe castle and bawn represent a fascinating example of how Gaelic Irish families adapted to new military technologies and architectural styles during a turbulent period of Irish history, blending traditional defensive needs with early modern innovations in fortification.