Doon.-- river, Ayrshire; issues from Loch Doon, on the Kirkcudbrightshire border, and flows NW., dividing the districts of Carrick and Kyle, to the Firth of Clyde 1½ mile S. of Ayr; is 26½ miles long, and is a good fishing stream. On Castle Island, in Loch Doon (5½ miles long), is a ruined tower called "Balliol's Castle." Near this islet, in 1826, nine ancient canoes were found sunk in the loch.

(John Bartholomew, Gazetteer of the British Isles (1887))