St Doulagh's Church () is the oldest stone-roofed church still in use in Ireland. It is situated approximately 10 kilometres from Dublin city, just north of the hamlet of Balgriffin, within Fingal and in the traditional County Dublin, and is marked as "St Doulagh's Church, Balgriffin". Its complex also comprises an octagonal baptistry built over a holy well - Ireland's only surviving standalone baptistry - and a stone housing over a pool. St Doulagh's is one of the two churches in the Church of Ireland "United Parishes of Malahide, Portmarnock and St Doulagh's. History and status The oldest part of the church as it stands is medieval dating from the 12th century, and believed to have been home to a small monastic settlement. However, according to studies on the site, Christian activity here dates back to the time of St. Patrick. Hudson (2005) states that King Sitric of Dublin gave land at St Doulough's, Portrane and Reachrain (probably Lambay Island) to Holy Trinity (Christ Church Cathedral, Dublin). In 1179, Pope Alexander III gave the "church lands at Clochar" to Laurence O'Toole, Archbishop of Dublin, so it was already church land - but there was no mention of a building. In regard to the other sites mentioned in the papal document, buildings are noted, suggesting that there may have been no useful building then at St Doulough's. The Canons Regular of St Augustine had by then been administering Christ Church. It seems possible that construction of the present building started about that time. However, there is no mention of a church at St Doulough's in the papal taxation lists of the early 14th century. It is not until 1406 that the first definite mention of a church at St Doulough's is made, when indulgences were granted by the Archbishop of Armagh to all who visited the church of St Doulough in the diocese of Dublin and confessed their sins to the resident chaplain Eustace Roche, and made a payment to the church. Rachel Moss believes that the church referred to is the eastern end of the medieval building and speculates that the funds generated may have then spurred building expansion. It seems likely from all this that construction of the present building started soon after the granting of the site to Holy Trinity by the Pope, and that additions and alterations were made in succeeding centuries, the dates of which are