- Category: Water Feature
- Type: Island
- Latitude/Longitude: 50°3'52"N 5°44'34"W
- Eastings/Northings: 132236, 25002
- OS Grid: SW322250
- Mapcode Local: GBR DX6H.VM2
- Mapcode Global: VH05L.DMSR
Location and coordinates are for the approximate centre of Tal-y-maen within this administrative area.
Geographic features and populated places may cross administrative borders.