Location and coordinates are for the approximate centre of Merthyr within this administrative area. Geographic features and populated places may cross administrative borders.
Gazetteer of the British Isles (Edinburgh: Bartholomew, 1887). John Bartholomew
Merthyr, par. and vil., in co. and 4 miles W. of Carmarthen, on river Cowin, 2218 ac., pop. 262.