Carlingford Lough is a glacial fjord or sea inlet in northeastern Ireland, forming 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, the Mourne Mountains, and the town of Warrenpoint; on its southern shore is County Louth, the Cooley Mountains and the village of Carlingford. The Newry River flows into the loch from the northwest.
Looking east, with Warrenpoint at centre
Image: Carlingford Lough locator
Carlingford Lough looking towards the Mournes
Republic of Ireland–United Kingdom border
The Republic of Ireland–United Kingdom border, sometimes referred to as the Irish border or British–Irish border, runs for 499 km (310 mi) from Lough Foyle in the north-west of Ireland to Carlingford Lough in the north-east, separating the Republic of Ireland from Northern Ireland.
The border at Killeen (viewed from the UK side) marked only by a metric (km/h) speed limit sign
A Sinn Féin protest against a hard border. Post-Brexit border controls are a controversial issue.
A bilingual traffic sign in County Louth, in the Republic of Ireland, warning drivers travelling south across the border that metric speed limits are used in ROI, whereas the UK uses imperial units in driving.
