This is the cathedral of the Catholic diocese of Clonfert. The building was designed in neo-Gothic style by architect William Byrne in 1897. The richly decorated interior is an instance of the 19C revival of Celtic art. Construction was financed by Edward Martyn and his relations, the Smyth family of Masonbrook. The stained-glass windows were made by Sarah Purser, Hubert McGoldrick and Evie Hone, who worked under An Tùr Gloine, and by Patrick Pye and Michael Healy.