KILFENORA CATHEDRAL is dedicated to St. Fachtna, who founded his monastery here during the sixth century. The original church was probably wooden and was later replaced by a stone building. Murrough O'Brien burned the abbey church in 1055 and killed many of the inhabitants. Repairs were carried out between 1056 and 1058 but the building was plundered in 1079 and accidentally burned in 1100. The present structure dates from between 1189 to 1200.

Reference: http://www.clarelibrary.ie/eolas/coclare/places/kilfenora_interest.htm