Pakistan River is composed of two major rivers, the Indus and the SWAT. The Indus is the longest river in Pakistan, stretching over 1, 800 miles and flowing through the country from the Himalayas to the Arabian Sea. The SWAT River is a tributary of the Indus, originating in the Hindu Kush mountain range and flowing through the Khyber Pakhtunkhwa province of Pakistan. Both rivers are important sources of irrigation and hydroelectric power for the country.