Payaswini (Paachini, in Tulu and local Malayalam) also known by the name Chandragiri, is a river in the Kasaragod district, state of Kerala, India. The 17th century Chandragiri fort is on the river. This river is considered as the traditional boundary between the Tulu Nadu and Malayalam regions of Kerala. The river originates in the village Koinadu in the Kodagu district, state of Karnataka. It flows in a north-westerly direction through Sullia taluk of the Dakshina Kannada district. In Sullia taluk, it is the major water source for domestic and agricultural purposes. It then flows west to Kasaragod district, state of Kerala to join the Arabian sea.