The town of Monaghan, owes its existence to the fortified crannogs of the MacMahons, the abbey of the Franciscans (built in 1462 destroyed in 1530 by the English) and in later times to the placement of an English garrison there in 1601. The county town of the County of Monaghan - one of three counties of Ulster sited in the Republic of Ireland, Monaghan is a busy market town with a rich architectural heritage.

A map of the town from 1602 shows a star shaped fort, houses, the remains of the abbey and the remains of the two crannogs in the nearby convent lake.

Many of the houses in the town are said to have been built with the stone of the town walls. The town as it exists today is a product of the late 18th and early 19th centuries when its layout was formalised into the sequence of streets and squares visible today.

Unlike many northern towns, Monaghan has a irregular plan, radiating triangularly from the centre. Many of the streets are short, acting as links between the four major squares - the Diamond, Church Square, Market Square and Old Cross Square.

Many of the buildings are built from local limestone and in recent years many stuccoed buildings have had their stonework cleaned and restored. A feature of the town is the use of softly rounded corners causing many of the open spaces to seemlessly blend into each other.