Other current and historical names
Location and coordinates are for the approximate centre of Ystradgynlais within this administrative area. Geographic features and populated places may cross administrative borders.
Gazetteer of the British Isles (Edinburgh: Bartholomew, 1887). John Bartholomew
Ystradgunlais, par., Brecknockshire, 1½ mile NE. of Ystalyfera sta. and 12½ miles NE. of Swansea, 21,954 ac., pop. 4114; P.O., T.O.; consists of two townships - Lower Ystradgunlais, pop. 3592; Upper Ystrad-gunlais, pop. 522; has collieries and ironworks.