Limerick's ancient cathedral was founded in 1168 by Donal Mór O'Brien, king of Munster. Parts of the 12th-century Romanesque western doorway, nave and aisles survive, and there are splendid 15th-century black-oak misericords (for supporting 'clerical posteriors') in the Jebb Chapel, unique examples of their kind in Ireland and each fabulously carved with creatures and mythical animals. Call ahead to confirm opening hours and to check if there are any musical events scheduled.