Karatoya River  Karatoya River (also spelt Korotoa River) (), a small stream in Rajshahi Division of Bangladesh, was once a large and sacred river. A channel of it presently flows by the ancient ruins of Mahasthangarh (or Pundranagara, ancient capital of Pundravardhana) in Bogra District. The "Karatoya mahatmya" bears testimony to its past greatness. In the "Mahabharata" it is mentioned that a visit to the Karatoya after three days’ fast produces the same merit as an aswamedha (horse killing) sacrifice. Another ancient city, Sravasti, may have been located on the banks of the Karatoya, north of Mahasthangarh. However, there is a controversy about the possible location of Sravasti. The Karatoya, known as Phuljhur rises in the Baikunthapur jungles in the extreme north-west of Jalpaiguri district (West Bengal, India) and forms for some distance the boundary between Dinajpur and Rangpur districts. It, then, meanders through Rangpur and Bogura. In the south of Bogura district, it receives the Halhalia and the united stream is then known as Phuljhur. It leaves Bogura at Chanda kona and flowing in a southerly direction past Raiganj and Shujapur is joined by the Ichhamati at Nalka. The Phuljhur then flows south past the important village of Ullapara, a few miles below which it joins the Hurasagar at Narnia after a course of about in this district. After this junction, it takes the name of Hurasagar and passing close by Shazadpur and Hera joins the Jamuna near Bera. The Karatoya is mentioned in the Puranas and had a high repute for sanctity. It was the eastern boundary of the old kingdom of Paundravardhana, the country of the Paundras which it separated from Kamrupa. It is shown in Van Den Brouk's map of Bengal (C, 1660) as flowing into the Ganges and in fact. before the destructive floods of 1787 it brought down to the Atrai and to the Ganges a great volume of Teesta water. Since the main stream of the Teesta was diverted to the east in 1787, the Karatoya and the Phuljhur have gradually silted up. and they are at the present day rivers of minor importance.