Monaghan is a town rich in architectural heritage, its earliest map dates from 1590 and shows only ‘the abbie of Mounachin’ and the ‘McMahon’s House in the Loughe of Mounachin’. The Franciscan abbey, erected c. 1462, was in the centre of what is the present town, while McMahon’s crannóg was on the Convent Lake. From 1513 to 1589 it was the headquarters of chiefs of the McMahons, whose power was eventually broken by the English in the late 16th, early 17th Century.

Monaghan was basically a Presbyterian town for the next 2 centuries and a colonial centre of commerce and local government. Many of Monaghan’s finest buildings date from the 18th and 19th Centuries.