- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 53°7'46"N 3°51'1"W
- Eastings/Northings: 276286, 360753
- OS Grid: SH762607
- Mapcode Local: GBR 62.6TBS
- Mapcode Global: WH54R.TLMQ
Location and coordinates are for the approximate centre of Llyn Geirionydd within this administrative area.
Geographic features and populated places may cross administrative borders.