- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°51'12"N 5°20'8"W
- Eastings/Northings: 170384, 222486
- OS Grid: SM703224
- Mapcode Local: GBR C2.TK6P
- Mapcode Global: VH0TK.GNMW
Location and coordinates are for the approximate centre of Ynys Gwelltog within this administrative area.
Geographic features and populated places may cross administrative borders.