The Cathedral of Saint Brendan, as it is properly known, contains what many consider the finest collection of Irish Arts and Crafts ecclesiastical decoration assembled under one roof, a fact that sits quietly at odds with the modest scale of the town around it.

Construction began in 1897 to a design by William Byrne, though the interior took decades to accumulate its remarkable contents. The project drew in some of the most significant figures of the Irish arts revival, among them Sarah Purser, who established the An Túr Gloine cooperative stained glass studio, and whose network of artists contributed windows, embroidery, sculpture, and metalwork to the building over the course of the early twentieth century. Evie Hone, Michael Healy, and A.E. Child all produced stained glass for the interior, making the cathedral an unusual repository of work that spans several generations of the same artistic movement. The Loughrea banners, a series of embroidered processional panels worked in the early 1900s, are among the more quietly celebrated textile commissions of the period in Ireland.

The church sits near the centre of Loughrea and is generally accessible during daylight hours. Visitors who arrive expecting conventional Victorian Catholic church interiors are usually caught off guard by the quality and coherence of what is inside, particularly the glass, which changes considerably depending on the light and the time of day.