Location and coordinates are for the approximate centre of Castletown within this administrative area. Geographic features and populated places may cross administrative borders.
Gazetteer of the British Isles (Edinburgh: Bartholomew, 1887). John Bartholomew
Castletown, vil., Olrig par., N. Caithness-shire, at S. corner of Dunnet Bay, 5 miles SE. of Thurso, pop. 932; P.O., T.O., 1 Bank; adjacent is the great Castlehill flag quarry, to which the vil. owes its prosperity.