Leinster is one of the four provinces of Ireland, situated in the southeast and east of Ireland. The province comprises the ancient Kingdoms of Meath, Leinster and Osraige. Following the 12th-century Norman invasion of Ireland, the historic "fifths" of Leinster and Meath gradually merged, mainly due to the impact of the Pale, which straddled both, thereby forming the present-day province of Leinster. The ancient kingdoms were shired into a number of counties for administrative and judicial purposes. In later centuries, local government legislation has prompted further sub-division of the historic counties.
Leinster has no official function for local-government purposes. However, it is an officially recognised subdivision of Ireland and is listed on ISO 3166-2 as one of the four provinces of Ireland. "IE-L" is attributed to Leinster as its country sub-division code.
Wikipedia https://en.wikipedia.org/wiki/Leinster
Coordinates 53°8'8.949" N -6°58'8.179" E