- Category: Water Feature
- Type: Island
- Latitude/Longitude: 52°0'31"N 5°5'18"W
- Eastings/Northings: 188140, 238974
- OS Grid: SM881389
- Mapcode Local: GBR CF.HLJN
- Mapcode Global: VH1QC.RSB0
Location and coordinates are for the approximate centre of Tri Maen-trai within this administrative area.
Geographic features and populated places may cross administrative borders.