Historic county of Wales
Carmarthenshire
Sir Gaerfyrddin
Tywi through the heart, Carmarthen Bay south, Black Mountain rising east.
Carmarthenshire / Sir Gaerfyrddin is organised around one of the great river valleys of south-west Wales. The Tywi crosses a broad and fertile central corridor before reaching the bay, while other river systems drain the western and southern country.
Northwards and eastwards the land rises into quieter hill country and eventually the Black Mountain. The county therefore moves from estuary and coastal lowland through rich river country towards increasingly upland terrain. Its familiar pastoral character is real, but only part of a geography which also contains industrial, maritime and mountain landscapes.
- Early roots in Ystrad Tywi
- Formed of the ancient Welsh Cantrefs of Mawr, Bychan and Emlyn
- Home to the National Botanic Garden
- Area: 937 sq miles / 2,427 km²
- Population: 184,232
- County top: Fan Foel 2,562 ft / 781 m
County geography
Current Census
Contemporary Census profile
England and Wales Census 2021. Detailed contemporary statistics are available in the Geographic County Census Explorer.
- Population density
- 201.5 people per sq mi (77.8 people per km²)
- Population
- 188,510
The Tywi basin
The Tywi is Carmarthenshire’s principal geographical thread. Its wide valley creates a natural route across the county and supports some of its richest agricultural land.
Tributaries descend from the surrounding uplands, reinforcing the river’s central role in tying together otherwise varied districts.
Bay and southern lowlands
Carmarthen Bay gives the county a broad maritime opening. Estuary, marsh, pasture and lower river country create a softer landscape than the hillier interior.
Further east, the southern county becomes increasingly shaped by the industrial history of the wider coalfield fringe.
Rising inland
North and east of the main valleys, Carmarthenshire becomes progressively higher and more sparsely settled.
The approach to the Black Mountain creates the strongest contrast with the low southern and western country, giving the county a clear progression from coast to upland.
County questions
Questions about Carmarthenshire
Is Carmarthenshire simply a coastal and farming county?
No. Agriculture is important, but the county also contains upland, river, estuarine and industrial landscapes.
County record
Names and continuity
- Formal name
- County of Carmarthen
- Local name
- Sir Gaerfyrddin
- Foundation
- 1284
Carmarthenshire and Sir Gaerfyrddin are forms associated with the county. Its older territorial background lies in the Tywi country of south-west Wales, while the river remains the clearest way to understand the county today.