This imposing four-storey limestone tower, now a National Monument in state ownership, tells a fascinating story of architectural evolution spanning several centuries. What began as a medieval hall house has been transformed through successive phases of modification, each leaving its mark on the building’s fabric.

The castle’s earliest incarnation dates to the late 13th century, when it likely stood as a two-storey hall house with its entrance at first floor level. The rough base batter that still wraps around the structure survives from this period. During the later medieval era, the building underwent significant remodelling into a proper tower house; workers inserted a ground floor doorway, added two more storeys with timber floors, installed a defensive machicolation, and topped it all with a steep gabled roof. The 16th and early 17th centuries brought further refinements, including gun loops for firearms defence and the addition of three tall chimney stacks. The two diagonally set chimneys on the western side reflect architectural fashions of the early 1600s, whilst the installation of large fireplaces at this time rendered the old machicolation obsolete, with one fireplace actually blocking access to it.

The castle served as a stronghold of the Bourkes, descendants of the Anglo-Norman de Burghs, for centuries. A 1584 map drawn by John Browne, Sheriff of County Mayo, labels it “MacWilliam’s House”, referring to the title MacWilliam Íochtar held by the elected chief of the Mayo Bourkes. Though the building now stands roofless with its interior gutted, the remaining structure preserves remarkable details: stone corbels that once supported timber floors still project from the walls, water spouts jut from the parapet level, and remnants of render cling to the interior walls. The castle remained in Bourke hands until 1629, when it was mortgaged to Valentine Blake of Menlough, marking the end of an era for this remarkable survivor of Ireland’s turbulent medieval past.