This circular tower house, once owned by Edmund Prendergast of Newcastle according to the Civil Survey of 1654-6, was already described as 'ruinous' in the mid-17th century. The survey noted that the lands had been abandoned, being too close to mountains and woods "where Tories usually frequent", a telling reminder of the lawlessness that plagued these borderlands during that turbulent period.

Today, only the northeastern, northwestern and southwestern portions of the tower survive, built from red sandstone and quartz rubble with traces of lime render still visible on the exterior. The circular structure, with an internal diameter of 4.6 metres and walls 2.6 metres thick at the base, originally rose at least three storeys high. The ground floor features partial remains of defensive embrasures and a round-headed window flanked by circular gun-loops at the northwest side; clear evidence of the castle's defensive purpose. The first floor, which was supported by wooden beams as indicated by surviving beam-holes, contains similar defensive features including another round-headed window with shot-holes on either side.

A particularly interesting architectural detail is the circular corbelled vault that once covered the first floor, with the western portion still showing impressions from the wicker centring used in its construction. When the Ordnance Survey visited in 1840, they recorded that the castle had belonged to the Prendergasts and measured 19 feet in diameter, though more of the structure survived then than what remains today. A fallen chunk of masonry lies east of the tower, whilst 120 metres north, an ogee-headed window head from the tower house has found new life as decoration on a roadside gate pier; a poignant reminder of how these ancient structures continue to be repurposed by local communities.