Lake Gosh lies in the Tavush region, near the village of Gosh, in the forest zone of Dilijan National Park, within the Aghstev River basin. It is a landslide-dam lake, formed when a shifting slope mass created a natural barrier.
The lake is about 100 m long, 80 m wide, with a maximum depth of 8 m, fed by precipitation and groundwater. In summer the water temperature is about 14°C.