The Round Tower was constructed during the 9th century, Kilkenny’s oldest structure. Tourists are allowed to climb to its 100 foot height. It adorns the 13th century St Canice’s Cathedral. This gothic-design church replaced predecessors, the earliest one named Cill Channigh from the 6th century. The cathedral’s namesake is Cainnech of Aghaboe. Saint Canice was a 6th century missionary and one of the Twelve Apostles of Ireland.