Kosi River, one of the main rivers in Bihar
and a prominent tributary of the Ganges
, originates in the Himalayas
. It flows through Nepal and northern India. This 724 kilometer-long river has several tributaries - most of which are smaller rivers flowing through eastern Nepal. A rope bridge on the river in Bihar is a popular tourist attraction. Due to its unpredictable floods, Kosi River is also known as 'the sorrow of Bihar'.