The Pro Cathedral — formally St Mary's Pro-Cathedral — is Dublin's principal Catholic church, a handsome Greek Revival building completed in 1825 on Marlborough Street. It is 'pro' cathedral because the Catholic Church considers St Patrick's Cathedral in the Liberties the rightful seat of the Archbishop, occupied by the Church of Ireland since the Reformation.
The building's Ionic portico is based on the Temple of Theseus in Athens. Inside, the church is famous for the Palestrina Choir, one of the finest boy choirs in Ireland, which sings at the 11am Sunday mass. Visitors are welcome outside of service times.