The Yarlung Tsangpo, also called Yarlung Zangbo (Tibetan: ཡར་ཀླུངས་གཙང་པོ་, Wylie: yar kLungs gTsang po, ZYPY: Yarlung Zangbo) is the upper stream of the Brahmaputra River located in the Tibet Autonomous Region, China. It is the longest river of Tibet and the fifth longest in China. The upper section is also called Dangque Zangbu meaning "Horse River." Originating at Angsi Glacier in western Tibet, southeast of Mount Kailash and Lake Manasarovar, it later forms the South Tibet Valley and Yarlung Tsangpo Grand Canyon before passing into the state of Arunachal Pradesh, India. Downstream from Arunachal Pradesh the river becomes far wider and is called the Siang. After reaching Assam, the river is known as Brahmaputra. From Assam, the river enters Bangladesh at Ramnabazar. From there until about 200 years ago it used to flow eastward and joined the Meghna River near Bhairab Upazila. This old channel has been gradually dying. At present the main channel of the river is called Jamuna River, which flows southward to meet the Ganges, which in Bangladesh is called the Padma. When leaving the Tibetan Plateau, the river forms the world's largest and deepest canyon, Yarlung Tsangpo Grand Canyon.
