The castle's history stretches back centuries, with John Kennedy recorded as its proprietor in 1640. By the time of the Civil Survey in 1654-6, the structure was noted as being 'paretly repaired at the Common Wealthes charge', suggesting it had seen recent renovation work during the Cromwellian period. The survey also mentions a 'little barbicon', indicating the castle had some defensive outworks typical of fortifications from this era.

The castle itself was a rectangular limestone building, constructed from roughly coursed rubble in a style common to Irish tower houses. According to measurements taken during the Ordnance Survey Letters, the interior dimensions were approximately 20.5 feet east to west and 29.75 feet north to south, with walls an impressive 6.5 feet thick; substantial enough to withstand siege warfare of the medieval period. The southeast corner appears to have housed a spiral staircase, a standard feature that would have provided access to the upper floors whilst taking up minimal space and offering defensive advantages.

Unfortunately, this piece of Irish heritage met an inglorious end in the late 1970s when commercial quarrying operations completely destroyed the castle and its associated bawn. Today, visitors to the site will find only a large pond where this medieval stronghold once stood, a stark reminder of how quickly centuries of history can be erased by modern industry. The loss of Dunalley Castle represents not just the destruction of stone and mortar, but the erasure of a tangible link to Tipperary's turbulent past.