The Tunga River (alternatively spelled Thunga) is a river in Karnataka state, southern India. The river is born in the Western Ghats on a hill known as Varaha Parvata at a place called Gangamoola. From here, the river flows through two districts in Karnataka - Chikmagalur District and Shimoga District. It is 147 km long and merges with the Bhadra River at Koodli, a small town near Shimoga City, Karnataka. The river is given the compound name Tungabhadra from this point on. The Tungabhadra flows eastwards and merges with the Krishna River in Andhra Pradesh.
The river is famous for the sweetness of its water and is considered to be the sweetest water in the world. There is a belief that " Thunga pana Ganga snana" which means we should drink the water of river thunga and take bath in river Ganga.
It has a dam built across it at Gajanur, and a larger dam has been built across the compound Tungabhadra river at Hospet.
Sringeri, on the banks of the Tunga, has several temples, the most important being the Śhāradā temple and the Vidyāśhankara temple.