The Himalayas

The longest river entirely within India and the sacred lifeline of northern and eastern India. Formed by the confluence of the Bhagirathi and Alaknanda rivers at Devprayag, flowing 2,525 km before draining into the Bay of Bengal through the vast Sundarbans delta.

The second-largest tributary of the Ganga and the longest tributary in India. Originating from the Yamunotri Glacier in the Lower Himalayas, it flows for 1,376 km through Uttarakhand, Himachal Pradesh, Haryana, Delhi, and Uttar Pradesh before merging with the Ganga at Triveni Sangam, Prayagraj.

Trans-boundary river of immense hydraulic volume. Originating on the Tibetan Plateau (as the Yarlung Tsangpo), it cuts through the Himalayas at the Great Bend (Namcha Barwa) into Arunachal Pradesh as the Siang/Dihang, flows across the 700-km Assam Valley, and forms the world's largest river island (Majuli).

Extensive, fertile alluvial depositional plain covering approximately 700,000 sq km between the Himalayas in the north and the Peninsular Plateau in the south. Formed by sediment transported by the Indus, Ganga, and Brahmaputra river systems.