This medieval stronghold, measuring approximately 10.6 metres by 7.5 metres internally with walls 2 metres thick and rising to about 10.6 metres high, once formed part of the ecclesiastical holdings of the bishops of Limerick. The tower’s three unvaulted levels, connected by a staircase in the northeast corner, each featured fireplaces in the west wall, whilst subsidiary rooms sat above what was once the eastern entrance. Today, ivy obscures much of the exterior, and derelict sheds clutter the interior, though one pointed limestone window on the west end remains intact amongst its otherwise broken and disfigured counterparts.

The site’s history stretches back to at least 1201, when it was known as Cluainclaidmech and held by the Church of Limerick. The area takes its name from the Fir Tawnagh tribe, giving rise to various spellings including Maytaueny, Moytawenagh, and eventually Mahoonagh. Through the centuries, ownership passed through numerous hands; from the de Clare family in the late 13th century to the McGibbons in the 1580s, then to Sir Henry Ughtred, and by 1640, Colonel Francis Courtnay possessed the property. The 1654-56 Civil Survey noted the castle was “in good reparation” with a mill seat, though earlier accounts suggest it may have been erected around 1490 by the Fitzgeralds. Intriguingly, Lewis’s 1837 description mentions a “curious circular building with a high conical roof of stone” nearby, which appears on the 1897 Ordnance Survey map and was considered a strong fortress in its own right.

The surrounding landscape adds further historical depth to the site, with the ruins of Mahoonagh Church and its graveyard lying just 125 metres to the east-northeast. The adjacent Castle Mahon house, built around 1780, now stands derelict itself; a three-bay, two-storey farmhouse with later additions including a porch with canopy and various lean-to structures. During the tumultuous period of the 1641 rebellion, Mr. Escott held the castle before being expelled, with some English residents reportedly hanged at nearby Mayne. Despite its current state of decay, the tower house remains an evocative reminder of the complex layers of ecclesiastical power, colonial settlement, and local tribal heritage that shaped this corner of County Limerick.