Guinea–Sierra Leone border

The Guinea–Sierra Leone border is 794 km (493 m) in length and runs from the Atlantic Ocean in the west to the tripoint with Liberia in the east.

[1] The border starts in the west at the Atlantic coast, and then proceeds overland in a north-easterly direction via various irregular and some straight lines, as well as the Great Scarcies River, before reaching the 10th parallel north.

[2] The boundary then follows this parallel eastwards for circa 75 km (47 m), before proceeding in a south-westerly direction, cutting across the Loma and Tingi Mountains, down to the Meli river.

The process culminated in the Berlin Conference of 1884, in which the European nations concerned agreed upon their respective territorial claims and the rules of engagements going forward.

[3] Britain and France confirmed the new French-Guinea-Sierra Leone boundary line in June 1911 and signed a treaty to this effect on 4 September 1913.