- The Cathedral of the Immaculate Conception dominates the Sligo skyline.
- It opened on the 26th July, 1874 by Cardinal Paul Cullen of Dublin, the Cathedral was consecrated on the 1st July, 1897 and dedicated in honour of the Immaculate Conception of the Blessed Virgin Mary.
- The Diocese of Elphin again had a Cathedral after a three hundred-year lapse in the wake of the Elizabethan Reformation.
- The man responsible for the building of the Cathedral was Bishop Laurence Gillooly. Born near Roscommon he studied in Paris before ordination as a Vincentian Priest in 1847.
- The three-faced clock tower, designed by Gillet & Bland of London in 1877, is one of the finest examples of a nineteenth-century turret clock, and the carillon, comprising nine bells, has few comparable to it in Ireland.
- The largest weighs 1,456 kg, and is dedicated to Our Lady. All the bells are beautifully decorated with the harp and shamrock and the chimes are a familiar sound to all Sligo natives.
