Founded by St. Brendan in the 6th century, there are three churches, two ogham stones and a number of early Christian and medieval grave slabs on the site of Ardfert Cathedral today.

The earliest building is the Cathedral which dates from the 12th to the 19th centuries. It has a fine Romanesque west doorway, a 13th century east window and a row of nine lancets in the south wall.

Two effigies of ecclesiastical figures of late 13th to 14th century which were mounted on either side of the east window are on view in the South Transept. One of the two smaller churches is a fine example of late Romanesque and the other, Temple na Griffin, is a plain 15th century structure with an interesting carving of a wyvern on one of the windows.