Records from 1574 show the fortress was then held by Conogher O’Kelly, a member of one of Galway’s prominent Gaelic families. The O’Kellys were powerful lords in this region, and their castles dotted the landscape as symbols of their authority during a turbulent period when Gaelic and English influences competed for control of Ireland.

Today, visitors to the site will find no trace of the castle that once commanded this strategic position. The structure met its end not through siege or abandonment, but through the more mundane forces of industrial progress; quarrying operations in the area systematically dismantled whatever remained of the medieval stronghold. This destruction likely occurred gradually, with stone from the castle repurposed for local building projects, a common fate for many of Ireland’s abandoned fortifications.

The loss of Newcastle Castle represents a familiar story across the Irish countryside, where countless tower houses and fortified dwellings have vanished from the landscape. What survives is the documentary evidence; the castle’s mention in 16th century records, preserved by historians like Nolan and O’Flanagan, ensures that even though the physical structure is gone, its place in the complex tapestry of Galway’s medieval history remains recorded. The site now serves as a reminder of how quickly tangible heritage can disappear when preservation isn’t prioritised, leaving only archival traces of what once stood as monuments to power and prestige.