Ganges Watershed

The Ganges is a watershed.  It is more or less circular.  It is isn't really belt-shaped.  There are hundreds of rivers involved.  McDogm 

Ganges And Yarlung Zangbo

The Ganges meets the Tibet River near Dhaka.  It is known as the Brahmaputra.  Tibet's civilization extends north to the Mongol, who are Tibetan Buddhists.  It is a double river system.  As the Ganges dominates South Asian thought, this double body of water could be said to extend from the Indian Ocean to Lake Baikal and farther north.  Given the Mongol dominination of everything from Hokkaido to Hungary, this page is much bigger than a geography page.  McDogm