Measuring just 4.2 metres east to west and 2.8 metres north to south, this sturdy stone structure once served as the gatehouse to a larger fortification, though today it stands alone. The south face features a semicircular arched gateway that opens into a vaulted passage running straight through the building; whilst the original gate has long since vanished, two large hanging eyes on the inside walls still mark where it once swung. Shadows on the eastern wall and projecting stones at the northwest and southwest corners reveal where curtain walls once connected to the tower, creating what would have been a formidable defensive position.

The tower’s interior tells the story of its defensive purpose through its architectural details. The first floor, accessed via a lintelled doorway in the east wall that likely connected to the curtain wall’s walkway, contains a small chamber measuring roughly 3.1 by 1.8 metres. Light enters through narrow, splayed window embrasures in the north and south walls, whilst the west wall features an angled opening, probably a gun loop positioned to defend the southern approach. The second floor follows a similar pattern with windows in the east and west walls, and above this level, the walls narrow to a corbel course that supports sandstone slabs topped with slate roofing on iron beams; a practical Victorian modification to a structure that was reportedly reduced in height when its upper sections became unsafe.

Despite its martial appearance, remarkably little is known about the castle’s history. Writing in 1915, Coleman noted that “no historical associations of any kind are known in reference to this little castle”, leaving its builders and original purpose somewhat mysterious. Today, the tower shares its grounds with Ringmahon House, a late 18th or early 19th century residence that features a four-bay, two-storey front with basement and a three-bay porch. The house, with its hipped roof and western addition, now serves as a school, giving this historic site a continuing role in the community whilst the medieval tower keeps its silent watch over the grounds.