St. Crumnathy's Cathedral

The Cathedral of the Annunciation or simply Ballaghaderreen Cathedral was built in the neo-Gothic style from 1855 to 1860. The bell tower with a spire and a carillon of bells was added in 1912 by the project architect, William H. Byrne.

The Cathedral of the Immaculate conception is famous for being the only Norman-style church in Ireland. The church was constructed in 1874 by the Bishop of Elphin, upon deciding that the local diocese was in need of a larger space. It is also notable for its impressive spire and large apse in the sanctuary.

The 18th-century Cathedral of St John the Baptist is Sligo's Anglican cathedral. The Cathedral of the Immaculate Conception was almost certainly built on the site of a medieval hospital and parish church in honour of the Trinity, founded in the 13th century. Part of the medieval structure is included in the present west tower. When the German-born Irish architect Richard Cassels (1690-1751) came to Sligo in 1730 to design Hazelwood House for the Wynne family, he was also commissioned to build St John's Church.