- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 54°45'10"N 2°28'19"W
- Eastings/Northings: 369723, 539873
- OS Grid: NY697398
- Mapcode Local: GBR CF5H.M0
- Mapcode Global: WH921.0S5Q
Location and coordinates are for the approximate centre of Greencastle Tarn within this administrative area.
Geographic features and populated places may cross administrative borders.