The site consists of an oval earthwork measuring roughly 46 metres east to west and 42 metres north to south, defended by a wide fosse, or defensive ditch, that’s over 17 metres wide and 2.2 metres deep. Within the northwest corner of this earthwork, visitors can still see the ruins of a rectangular structure, believed to be a late 12th or early 13th century hall, with a four-storey tower built against its northern wall. Though much of the original hall has collapsed, with substantial masonry now lying in the fosse to the west, three wall fragments remain at the northwest, northeast and southeast corners, standing to two storeys despite missing much of their facing stones.

The attached tower, likely added during the 15th or 16th century as a tower house, tells its own story of medieval defensive architecture. While the western and southern walls have collapsed above the first floor, the northern and eastern walls still reach nearly their full height. The ground floor chamber, measuring 5.5 by 4 metres, features a rounded wicker-centred vault and a double-splayed window in the north wall. Each ascending floor reveals more architectural details: ogee-headed windows at various levels, fireplaces including one at the third floor decorated with geometric designs, and the remains of five rounded corbels at the northeast corner that once supported a corner bartizan. The tower’s internal layout includes what appears to be blocked stairs in the ground floor’s east wall recess, with mural stairs visible in the broken western wall rising from the third floor to the northwest corner.

The castle’s history is as layered as its architecture. Originally built by the de Cogans, it passed to the Earl of Desmond in 1439 before eventually coming into Barrett possession in the early 17th century. Local historian Windele, writing in the 1840s, recorded that a three-quarter round tower once stood on the south side but was demolished in 1835; no trace of this structure remains today. The site, also known as Castlemore, represents an excellent example of a Norman ringwork castle that evolved over centuries to meet changing defensive needs. The monument has been under preservation orders since 1938, recognising its significance to Ireland’s medieval heritage.