[1] The N54 begins at a junction with the N2 near Monaghan, and runs west through Clones until reaching the boundary of County Fermanagh in Northern Ireland.

[2] From here, it crosses through Drummully (also known as Coleman's Island),[3][4] an almost detached part of County Monaghan in the Republic, connected to the rest of the country by only a few metres.

In 12 kilometres (7.5 mi), the main road between Clones and Cavan crosses the border four times.

[2] During The Troubles in the 1970s and the 1980s, many local roads leading into County Monaghan in the Republic were closed either by blocking with concrete, or being blown up by the British Army.

[5] As a result of Brexit, where the United Kingdom voted to leave the European Union and make the border an external EU border, the EU identified fifteen locations where customs or vehicle checks could potentially take place.