[6] According to one legend, the sage Vishvamitra through tapasya (penance, meditation and correct practices) acquired the power to create a whole new universe.

[1][8] It flows in a north-westerly direction through the plains of Mirzapur, then forms the boundary between Uttar Pradesh and Bihar, and finally joins the Ganges near Village Bara (East Side) Ghazipur Uttar Pradesh and Chausa (Bihar).

Total drainage area of the Karmnasa along with its tributaries is 11,709 square kilometres (4,521 sq mi).

[8] The Karmanasa reaches the plains by a succession of leaps, including three falls known as the Karkatgarh,Devdari and the Chhanpathar, which, from their height and beauty, are deserving of special notice.

[14] UP State Archaeology department under the direction of Rakesh Tewari, excavations has unearthed iron artifacts dated between 1200 – 1300 BC at Raja Nal Ka Tila site in Karmanasa river valley of north Sonebhadra.