The Karmanasa River is a tributary of the Ganges and flows through the states of Uttar Pradesh and Bihar. The name “Karmanasa” literally means "destroyer of religious merit” and has many legends attached to it.
The river accommodates two dams namely; the Latif Shah bund and the Nuagarh dam. The Grand Trunk Road also runs over a bridge on the Karmanasa river. Iron artifacts have been unearthed at Raja Nal Ka Tila in the river valley and are important to the history of iron-making in India.