Carlingford Lough is a glacial fjord or sea inlet that forms part of the border between Northern Ireland to the north and the Republic of Ireland to the south. On its northern shore is County Down and on its southern shore is County Louth. At its extreme interior angle (the northwest corner) it is fed by the Newry River and the Newry Canal.The name is derived from the Old Norse Kerlingfjǫrðr, which means "narrow sea-inlet of the hag". Historically it was called Cuan Snámh-Aighneach, Snámh-Aighneach or Cuan Cairlinne in Irish. An older English name was Nury (Newry) Bay.GeographyThe Newry River and the Newry Canal link the lough to the nearby city of Newry (the canal continues on towards the River Bann and Lough Neagh; the river, under the name River Clanrye, loops around County Down). The only other glacial fjords in Ireland are Lough Swilly and Killary Harbour.