- Category: Water Feature
- Type: Island
- Latitude/Longitude: 52°48'10"N 4°42'23"W
- Eastings/Northings: 217646, 326237
- OS Grid: SH176262
- Mapcode Local: GBR GPR9.2VR
- Mapcode Global: WH33M.NTZ5
Location and coordinates are for the approximate centre of Carreg Maen Du within this administrative area.
Geographic features and populated places may cross administrative borders.