- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 54°25'9"N 3°20'35"W
- Eastings/Northings: 312933, 503470
- OS Grid: NY129034
- Mapcode Local: GBR 5K2B.ZM
- Mapcode Global: WH712.M650
Location and coordinates are for the approximate centre of Flass Tarn within this administrative area.
Geographic features and populated places may cross administrative borders.