- Category: Water Feature
- Type: Island
- Latitude/Longitude: 51°43'51"N 5°28'47"W
- Eastings/Northings: 159794, 209311
- OS Grid: SM597093
- Mapcode Local: GBR DSV3.NNJ
- Mapcode Global: VH0V1.YRTG
Location and coordinates are for the approximate centre of Grassholm Island within this administrative area.
Geographic features and populated places may cross administrative borders.