Known locally as Cathair na Mionnain, meaning “Fort of the Kidgoats”, this once-formidable tower house now exists only as an overgrown mound of rubble and masonry fragments. When antiquarian Eugene O’Curry visited in 1839, he found nothing more than “a heap of ruins and rubbish”, yet pieces of the castle’s curved stairwell and dressed limestone blocks still remain, with some stored in nearby sheds as testament to its former grandeur.

The castle’s history is bound up with the powerful O’Brien dynasty who dominated Clare for centuries. Queen Elizabeth I granted the castle and manor to Conor O’Brien, 3rd Earl of Thomond, in 1560 as part of the Tudor policy of securing loyalty from Gaelic lords. By 1574, it had passed to Teige, son of Murrough O’Brien, and became a focal point of family drama when Murrough died there in 1591 before being buried at Kilfenora. The outbreak of the Nine Years’ War in 1598 saw Murrough’s sons, Turlough and Dermot Roe, join the Irish rebellion against English rule; however, their resistance was short-lived when Sir Conyers Clifford, Governor of Connaught, ordered Theobald Dillon to besiege the castle, forcing Turlough to surrender.

Today, visitors to the site will find a subrectangular platform measuring roughly 26 metres north to south and up to 25 metres east to west, rising 3.5 metres high, which likely formed the original bawn or defensive courtyard. The Cromwellian commissioners probably ordered the castle’s final dismantling in 1654, part of the systematic destruction of Irish fortifications following the Confederate Wars. Though reduced to ruins, Caherminnaun Castle remains an evocative reminder of the turbulent period when Gaelic lords navigated the dangerous waters between maintaining their traditional power and accommodating English colonial ambitions.