Carnlough translates in meaning to ‘Cairn of the Lake’ and lies at the outflow of Glencloy ('Glen of Hedges') one of the nine Glens of Antrim. The area has seen human settlement since the Neolithic period, the close proximity to the ocean for food, a fresh water outflow and the surrounding limestone cliffs rich in flint deposits for making tools, made ideal.

The village is noted for its picturesque harbour adjacent to the main Causeway Coastal Route, the harbour was built in 1853 by the Marchioness of Londonderry. The first harbour however was built in the late 1700s by a Phillip Gibbons who had married Ann Stewart (daughter of the Earl of Antrim’s Agent), it was a stone pier two hundred feet long which could accommodate ships up to twenty tons and was used for the export of potatoes, grain and limestone and the import of coal.

In 1834, the Marchioness of Londonderry, Francis Anne Vane-Tempest inherited the Carnlough Estate from her mother Anne Catherine McDonnell, Countess of Antrim, the eldest of three daughters of the 6th Earl of Antrim, William Randal MacDonnell. Francis Anne bought further land belonging to the Gibbons family. Along with her husband the ^3rd Marquis (Charles William Stewart) she pioneered the construction of the new harbour which included a road bridge and a 1.5km mineral railway line to the quarry which overlooks the village.

The harbour was built out of limestone blocks, shaped and brought down from the quarry, the primary function of the development was to take limestone from the quarries to the kilns and harbour for export and later with rail expansion, to the mill and whiting works. The harbour was eventually able to accommodate ships of up to 300 tons on the south pier.

The railway was operated by the Carnlough Lime Company and eventually extended to some 7km of track, the first part of the system opened in 1854 and ran for one mile over a 1:25 gradient to the quarries, it was originally operated by gravity and horse power but this was replaced by  cables with a winding house. Today you can follow the old line now converted to a footpath, from the harbour over the bridge and up to the quarries.