Built from limestone rubble with a distinctive base batter that slopes outward for the first 2.5 metres, the structure measures approximately 9 metres by 8 metres and rises to a height of 10 metres. The castle appears on the 1657 Down Survey map, when it belonged to Edward Nugent, described in contemporary records as an ‘Irish Papist’, and it remained a prominent landmark through to its depiction as a free-standing tower on Ordnance Survey maps of the 19th century.

The castle’s defensive features reveal the paranoia and ingenuity of its medieval builders. The main entrance, located off-centre in the northeast wall, leads into a lobby protected by a murder hole overhead; a grim reminder that unwelcome visitors could be dispatched from above. A pointed doorway connects this lobby to the ground floor chamber, which is lit by narrow slit windows. The interior preserves evidence of its original layout, including corbels and beam holes indicating wooden floors, whilst a mural staircase, now partially broken through the southeast wall, once provided access between levels. The first floor retains part of its stone barrel-vaulted ceiling, though sections have collapsed over the centuries, and various chambers throughout the tower feature defensive angle embrasures at the corners, allowing defenders to cover multiple approaches with minimal exposure.

Curious architectural details pepper the structure, from the weathered stone head carved into the external northwest wall at second floor level to the tiny corbel-roofed room tucked into the east corner of the third floor, accessible only by steep steps or ladder. The absence of any fireplaces throughout the tower suggests either that heating came from braziers or that comfort was a secondary concern to defence. Just east of the castle, set into the ridge, a circular masonry structure likely served as an ice house, whilst cropmarks visible in the surrounding fields hint at the broader landscaped demesne that once surrounded both the medieval tower and the later Newcastle House, a handsome Georgian residence built around 1830 that still stands nearby.