Situated on the grounds of the 6th Century monastery founded by St. Brendan, his namesake cathedral is the oldest church in Ireland with an unbroken history of public worship. According to Celtic legend, St. Brendan, accompanied by a large group of monks, sailed off in search of a mythic island paradise. After seven years, they reached The Isle of the Blessed, or Terra Repromissionis, an island paradise with lush vegetation. Brendan's narrative of the island makes the location difficult to determine. One interpretation supports a location not far off the west coast of Ireland. Another places the island further south, making it synonymous with the ancient "Fortunate Isles".
At one time Clonfert was a noted seat of learning with 3000 monks in residence. During the reign of Queen Elizabeth, it was a proposed location for the university which later became Trinity College, Dublin. In modern times, religious services occur only every month or so, usually when a priest comes to the parish as part of a rotating schedule. In between visits, the church is locked and in order to view it, you must secure the keys from the couple that live in a cottage adjacent to the church grounds.