This well-preserved tower house, measuring 13.1 metres east to west and 8.7 metres north to south, showcases the defensive architecture typical of 15th-century Ireland, though its story is one of changing allegiances and centuries of occupation. Built possibly by Lochlainn MacCon of the O’Connor family who controlled this district, the castle soon passed into the hands of the O’Briens, Clare’s dominant clan, who held it through various branches during the turbulent 1570s and 1580s.

The castle’s architecture tells a tale of both military pragmatism and domestic comfort across its unusual split-level design. The narrow eastern section rises to six storeys, containing the spiral stairwell and private chambers, whilst the broader western portion houses four floors of grand halls. Throughout the structure, ogee-headed windows pierce the thick limestone walls alongside defensive loops and arrow slits, creating an intriguing blend of elegance and fortification. The third floor boasts an ornate mantled fireplace with ‘1641’ inscribed on its keystone, marking renovations during one of Ireland’s most tumultuous periods, whilst machicoulis on the north and west walls provided defenders with positions to rain down projectiles on attackers below.

Despite falling into disrepair by 1654, Ballynalackan Castle refused to surrender to time; it was restored and occupied well into the late 18th century, with evidence of later modifications including replica ogee loops and Killaloe slate roofing typical of 18th and 19th-century Clare construction. The castle’s interior preserves fascinating architectural details including a secret chamber concealed within the thickness of the south wall, bolted from the outside, and a hexagonal chimney flue crafted from precisely carved stones. After centuries in various hands, the castle was sold to the O’Callaghans in 1938, and today stands within a large bawn, its limestone walls still bearing traces of original rendering and the scars of its long, eventful history.