- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°57'43"N 5°7'44"W
- Eastings/Northings: 185120, 233927
- OS Grid: SM851339
- Mapcode Local: GBR CC.LGG2
- Mapcode Global: VH1QK.1YS5
Location and coordinates are for the approximate centre of Ynys y Castell within this administrative area.
Geographic features and populated places may cross administrative borders.