This impressive fortification consists of a rectangular main tower measuring 12 metres east to west and 9.9 metres north to south, with a conjoined tower at the northeast corner adding another 6.15 by 6.3 metres to the structure. The main tower rises four storeys whilst the corner tower extends to six, creating a complex defensive arrangement typical of late medieval Irish castle architecture.

The castle’s interior reveals sophisticated planning across multiple levels. Entry is gained through doors in the south wall at both ground and first floor levels, with the ground floor chamber illuminated by a simple window. A straight mural staircase rises from the eastern side of the first floor doorway, providing access to both the first and third floors. The first floor chamber connects to mural passages in three walls; east, north and west; with the northern passage leading to the corner tower’s first floor. This level of the corner tower contains a garderobe chamber and a manhole providing access to an unlit dungeon below. The second floor sits beneath a pointed wicker-centred vault, whilst the third floor boasts large central windows on each face, covered by segmental vaults. The western window features a pair of stone seats, and the southern window is flanked by two identical carved stone heads on its exterior.

This stronghold served as the seat of the Clan Dermod branch of the MacCarthy Riabhach family until Crown forces captured it in 1603 following a prolonged siege. Archaeological excavations in 1998 and 2001 have added to our understanding of the site, revealing more about its construction and use during one of the most turbulent periods in Irish history, when Gaelic lordships were giving way to English colonial control.