The core of the structure is a tower house built by the Kirwan family in 1648, though what visitors see today is a complex blend of defensive fortification and Georgian refinement. During the 18th century, the original tower was incorporated into a larger house, with two wings added to create the mansion that exists today.

The tower house’s original features offer tantalising glimpses into its past as a fortified residence. In the basement, massive oak beams still rest on their original corbels, supporting the floor of what was once the main hall above. The eastern wing reveals broken corbels that once held up the battlements, suggesting the tower originally stood four storeys tall. Archaeological evidence points to several blocked-up windows on the north wall, their hood-mouldings still visible beneath centuries of weathering, whilst a semi-pointed doorway, now partially obscured by plaster, hints at the building’s medieval origins.

This blending of defensive architecture with later Georgian additions makes Cregg Castle a particularly interesting study in how Irish landed families adapted their homes over time; transforming stark military structures into more comfortable country houses whilst preserving elements of their ancestral strongholds. The castle represents a common pattern in Irish architecture, where practical fortifications evolved into symbols of status and continuity, with each generation leaving its mark on the building’s fabric.