A centre of A town is mass produced higher of little joe interconnecting squares: Open-air market (or even Street), Church Square, The Diamond, & Old Cross Square. Sited around Open-air marketplace is the Market Home (built 1792), now an picture gallery. A County Museum, which has won a Council of Europe Award for its display of history and archeology, is placed nearby. A virtually 100% spectacular building of all is St Macartan's Cathedral with its wonderful rosette & steeple. The Battle of Clontibret between a forces of Hugh O Neill & the Irish Crown was fought inside northern Monaghan around 1595. A territory of Monaghan got earliest been wrested from either a control of the MacMahon sept in 1591, after a leader of a MacMahons was hung by authority of the Dublin government; this was one of the cases that led to the Nine Years War (1595-1603) and a Tudor reconquest of Ireland.

Charles Gavin Duffy, the 1st premier of New South Wales in Australia, was a previous resident of Monaghan.

In 17 May 1974 seven people died around the terrorist incident in the town when the car bomb exploded during a Friday evening rush hour. This was one of a couple incidents in the Republic in the period of The Troubles in Northern Ireland; another bomb exploded on the equivalent day around Dublin in what became known as a Dublin and Monaghan Bombings.

Now a town occurs as prosperous & growing 1. These are the centre for the timber-frame home building industry & has the big article of furniture manufacturing industry. There is a campaign to boost touristry by reopening a Ulster Canal in a scheme which would finally allow boats to travel from either Northern Irish towns like Newry and Coleraine by way of Monaghan to places when far south when Limerick as well as to Dublin.