evidence: Carlingford Lough is a beautiful coastal inlet sandwiched between the Mourne Mountains in Northern Ireland and the Cooley Peninsula in the Republic of Ireland. [...] Straddling the border between Northern Ireland and the Republic of Ireland, Carlingford Lough is just south of the beautiful Mourne Mountains, right in front of Carlingford town. It is actually an inlet from the Irish Sea, 27km northeast of Dundalk and 100km north of Dublin. County Down lines the north shore and County Louth is on the southern bank. [...] The sheltered waters of Carlingford Lough are actually a rare glacial fjord or sea inlet marking the border between the Republic of Ireland and Northern Ireland.