The Surma-Meghna River System is a river complex in the Indian Subcontinent, one of the three that form the Ganges Delta, the largest on earth.[citation needed] It rises in the Manipur Hills of northeast India as the Barak River and flows west becoming the Surma River and then flows south as the Meghna River, a total of 946 kilometres (588 mi) of which 669 kilometres (416 mi) are within Bangladesh, to the Bay of Bengal.