Built around 1550 by the MacNamara clan, who controlled much of the region during the medieval period, the castle represents the typical defensive architecture favoured by Gaelic and Anglo-Norman families during this turbulent era. The four-storey limestone structure features the characteristic thick walls, narrow windows, and murder holes that made these fortified residences both practical homes and formidable strongholds.

The castle’s history reflects the broader patterns of Irish land ownership and conflict. The MacNamaras held Craggaunowen until the Cromwellian conquest of the 1650s, when it was confiscated and granted to new English settlers. By the 18th century, the tower house had been abandoned in favour of more comfortable Georgian residences, leaving it to slowly deteriorate. What makes Craggaunowen particularly noteworthy today is its meticulous restoration in the 1960s by John Hunt, the renowned medievalist and art collector, who transformed it into both his private residence and a showcase for his extensive collection of medieval artefacts.

Today, Craggaunowen forms part of a larger historical park that includes reconstructed crannogs, ring forts, and other examples of early Irish architecture. The castle itself houses Hunt’s collection, which includes the Brendan Boat; a leather currach used by Tim Severin to recreate St. Brendan’s legendary voyage to America. Visitors can climb the narrow spiral staircase to explore each floor, from the ground-level storage areas to the lord’s chamber at the top, gaining insight into how these tower houses functioned as both family homes and defensive structures in an age when raids and territorial disputes were commonplace.