Naini Lake is a natural freshwater lake, of tectonic origin, located amidst Nainital city of Uttarakhand. It is lunar-shaped and has an outlet at the south eastern end. Naini Lake is one of the four lakes in Kumaon hills, the three other being Sattal Lake, Bhimtal Lake and Naukuchiyatal Lake. Balia Nala is the main feeder-stream of the lake.