- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°50'36"N 1°1'0"W
- Eastings/Northings: 467840, 216550
- OS Grid: SP678165
- Mapcode Local: GBR 9ZM.7T6
- Mapcode Global: VHDTV.BXDQ
Location and coordinates are for the approximate centre of Grotto Island within this administrative area.
Geographic features and populated places may cross administrative borders.