Cahir Castle Is one of Ireland’s largest and best-preserved castles. It stands proudly on a rocky island on the River Suir. The castle was was built in the thirteenth century and served as the stronghold of the powerful Butler family. So effective was its design that it was believed to be impregnable, but it finally fell to the earl of Essex in 1599 when heavy artillery was used against it for the first time. During the Irish Confederate Wars it was besieged twice more. At the time of building,