The towering Gothic Revival cathedral that dominates the southern skyline of Monaghan. Designed by JJ McCarthy — the same architect responsible for many of Ireland's grandest 19th-century Catholic churches — it was begun in 1861 and consecrated in 1892, a long and expensive project funded almost entirely by parish subscriptions in the wake of Catholic Emancipation.
The interior is high, narrow, and rich in colour, with stained glass by Mayer & Co of Munich and a long chancel that culminates in a baldachin altar. Mass times are posted at the gate. The walk up the avenue from the town is short and worth the climb for the view back over Monaghan.