- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°56'42"N 5°12'24"W
- Eastings/Northings: 179700, 232246
- OS Grid: SM797322
- Mapcode Local: GBR C8.MM4P
- Mapcode Global: VH0T7.PCQT
Location and coordinates are for the approximate centre of Cerrig Gwylan within this administrative area.
Geographic features and populated places may cross administrative borders.