Once a rectangular stronghold measuring roughly 12 metres northwest to southeast and 8 metres northeast to southwest, this castle was recorded as belonging to one ‘Jhonick fitz Thoms’ in 1574, providing a tantalising glimpse into its Tudor-era ownership. The structure appeared on Ordnance Survey maps as late as 1920, marked as an unroofed building, and according to local memory, remnants of its walls stood until the early 1970s.

Today, visitors to the site will find no visible traces of the castle itself, though the land holds its secrets close. In August 1996, archaeologists investigated a small area of subsidence west of where the castle once stood, uncovering what appeared to be an earthen-cut passage running east to west. This narrow feature, approximately half a metre wide and extending for up to four metres, sparked debate amongst researchers; it could represent the remains of a souterrain, one of those mysterious underground passages often associated with early Irish settlements, or it might simply be a natural geological feature that time and earth movement have shaped.

The investigation revealed that whilst the passage seemed to terminate at its western end, local knowledge suggested it had once extended further before collapsing. Such tantalising hints are common at Ireland’s lost castle sites, where oral history and archaeological evidence combine to paint incomplete but fascinating pictures of the past. Though Knockaunnageeragh Castle has returned to the earth from which it was built, its story remains embedded in historical records, local memory, and the subtle depressions in the landscape that mark where medieval life once flourished.