- Category: Water Feature
- Type: Island
- Latitude/Longitude: 52°59'53"N 4°26'15"W
- Eastings/Northings: 236502, 347326
- OS Grid: SH365473
- Mapcode Local: GBR 59.H2H2
- Mapcode Global: WH43X.SWZW
Location and coordinates are for the approximate centre of Ynys Fawr within this administrative area.
Geographic features and populated places may cross administrative borders.