Lake Rara is situated in the western part of Nepal, at about 300 km northwest of Kathamndu, the capital of Nepal. It is a warm, oligotrophic lake with a monomictic type of water circulation. It is surrounded by hills and mountains from which more than 30 brooks flow into the lake. It has only one outlet, Khater Khola, on its western shore (khola=stream). Khater Khola forms a deep gorge at about 7 km downstream from the outlet and finally joins Karnali River, a tributary of the Ganga.

Lake Rara is somewhat oval in shape. It has relatively large maximum depth for its surface area. It has two basins. The main basin, occupying the western part of the lake, covers about 80% of the total surface area. It is characterized by a steep margin and vast flat bottom. The area below 160 m accounts for about 27 % of the lake area. The eastern sub-basin has a gently sloping margin and a small bottom. Lake Rara is a part of Rara Lake Naitonal Park and Wildlife Conservation Area (Q).