chief river of Lebanon, rising in a low divide west of Baalbek (Baalbeck) and flowing southwestward through the Al-Biqāʿ (Biqāʿ, Al-) Valley between the Lebanon (Lebanon Mountains) and Anti-Lebanon (Anti-Lebanon Mountains) mountains. Near Marj ʿUyūn it bends sharply west and cuts a spectacular gorge up to 900 feet (275 metres) deep through the Lebanon Mountains to the Mediterranean south of Sidon. The river's lower course is known as Qāsimiyyah. Although the river's total length is only about 90 miles (145 km), its waters irrigate one of Lebanon's most extensive farming regions, Al-Biqāʿ. The Litani River Authority, established in 1954, was to have provided for an increase in irrigated land, generation of electricity, and development of recreational areas; however, the main achievement of the project was later limited to the establishment of electrical power plants.