The Killeavy Castle is close to the Slieve Gullion Courtyard. Killeavy church is the site of one of Ireland's most important early convents founded by St Mo-Ninne in the 5th century. Although plundered by the Vikings in 923, monastic life continued by Augustinian Nuns until 1542. In earlier times it was a place of pilgrimage and miraculous cures were attributed to a nearby well.