Built around 1600, this well-preserved structure represents the final flourish of castle building in Ireland, constructed just as the medieval period was giving way to more modern times. The castle's thick limestone walls and defensive features tell the story of an era when local landowners still needed fortified homes to protect their families and holdings.

The castle's architecture follows the classic Irish tower house design, rising four storeys high with a distinctive rectangular plan. Its builders incorporated practical defensive elements including narrow window slits on the lower levels, murder holes above the entrance, and bartizans; small turrets projecting from the corners that allowed defenders to cover the walls below. Inside, the layout was surprisingly sophisticated for its time, with a spiral staircase connecting the floors, vaulted ceilings for fire protection, and chambers that served as both living quarters and storage spaces.

Today, Kiltullagh Castle remains remarkably intact despite centuries of weathering and neglect. The structure passed through various hands over the generations, serving as a residence until the 18th century when changing architectural tastes and political circumstances led to its abandonment. While ivy now clings to portions of its walls and the wooden floors have long since disappeared, the stone shell endures as a tangible link to Galway's past. Visitors can still make out the carved stone details around doorways and windows, evidence of the craftmanship that went into creating what was once both a home and a fortress.