Glamorganshire is a maritime county in southeast Wales, bounded on the northwest and north by Carmarthenshire and Breconshire, on the east by the English county of Monmouthshire, south and southwest by Bristol Channel. It covers 813 square miles.
The principal rivers are the Taff, Taw, Romney, and Neath. The surface in the north is hilly and rugged. The highest peak, Craig-y-Llyn, rises to 1971 feet. Between the mountains and the channel is the Vale of Glamorgan, known as the "Garden of Wales," one of the most fertile regions of Great Britain. Glamorganshire is chiefly important, however, for its coal resources. Cardiff is the county town.
Antiquities of the shire include numerous ancient castles, such as Pennard, Caerphilly (largest of Welsh castles), as well as Norman fortresses at Swansea and Oystermouth.