Gartan LoughGartan Lough, also known as Lough Beagh South, is a freshwater lake in the northwest of Ireland. It is located in north County Donegal close to the eastern boundary of Glenveagh National Park.GeographyGartan Lough is about west of Letterkenny. It measures about long and wide.HydrologyGartan Lough is fed by the Bullaba River entering at its southern end. The lake drains northeastwards into the River Leannan, which in turn enters Lough Fern.Natural historyFish species in Gartan Lough include Arctic char. Gartan Lough is part of the Leannan River Special Area of Conservation.