- Category: Water Feature
- Type: Bay
- Latitude/Longitude: 53°24'57"N 4°27'59"W
- Eastings/Northings: 236176, 393842
- OS Grid: SH361938
- Mapcode Local: GBR HMBN.YN9
- Mapcode Global: WH41Z.CDBN
Location and coordinates are for the approximate centre of Porth y Wylfa within this administrative area.
Geographic features and populated places may cross administrative borders.