The earthwork itself is impressive, measuring roughly 46 metres east to west and 42 metres north to south, with its flat top defined by a substantial fosse; a defensive ditch that’s 17 metres wide and over 2 metres deep on the southwestern side, whilst the northeastern edge drops away naturally down the steep valley slope.

The castle remains tell a story of construction spanning several centuries. At the heart of the site stand the fragmentary walls of what appears to be a late 12th or early 13th century hall, a rectangular structure that once measured about 16 by 10 metres. Only three corner fragments survive today, rising to two storeys, though much of their facing stones have been plundered over time. The northeastern corner preserves evidence of two window openings, one above the other, whilst architectural details like skewbacks and a draw bar socket indicate where the main doorway once stood in the eastern wall. A substantial pile of fallen masonry in the western fosse hints at the scale of what has been lost.

Built against the hall’s northern wall stands a better preserved four storey tower, likely added during the 15th or 16th century in the style of a tower house. Though its western and southern walls have collapsed above the first floor, the northern and eastern walls survive nearly to their full height. The ground floor chamber features a rounded vault made using wicker centering, a common medieval construction technique, whilst the upper floors contain various window styles including ogee headed lights and geometric decorated fireplaces. Particularly noteworthy is a window at the third floor level with its mullion positioned on the tower’s corner, a feature shared with Desmond Castle in Kinsale. The de Cogans were the original Norman builders, with the Earl of Desmond acquiring the castle in 1439, though the Barrett family, who gave the castle its current name, didn’t take possession until the early 17th century.