- Category: Water Feature
- Type: Bay
- Latitude/Longitude: 52°48'17"N 4°39'30"W
- Eastings/Northings: 220903, 326349
- OS Grid: SH209263
- Mapcode Local: GBR 50.W8W6
- Mapcode Global: WH33N.DRYK
Location and coordinates are for the approximate centre of Porth Alwm within this administrative area.
Geographic features and populated places may cross administrative borders.