Laid out around a round tower, the medieval ruins of Devenish Island have a charm that is enhanced by their romantic lakeside setting. St Molaise chose the island as the location in which to found a monastery in the 6C. Sacked by the Vikings, the site was nonetheless occupied during the Middle Ages by different religious congregations, as shown by the ruins of Lower Church (Teampall Mór) and St Mary's Priory.