- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°59'37"N 5°5'50"W
- Eastings/Northings: 187455, 237346
- OS Grid: SM874373
- Mapcode Local: GBR CD.JJBT
- Mapcode Global: VH1QK.L4MW
Location and coordinates are for the approximate centre of Carreg Bwch-du within this administrative area.
Geographic features and populated places may cross administrative borders.