Ganga

In Hinduism, the river Ganges is referred to as Gaṅgā

Gaṅgā is worshiped by Hindus who believe that bathing in the river causes the remission of sins and facilitates liberation from the cycle of life and death. Pilgrims travel long distances to immerse the ashes of their kin in the waters of the Ganges, bringing their spirits closer to nirvana.

Bhagiratha prayed to Brahma that Ganga come down to Earth. Brahma ordered Ganga to go down to the Earth and then on to the nether regions so that the souls of Bhagiratha's ancestors would be able to go to heaven. Ganga felt that this was insulting and decided to sweep the whole Earth away as she fell from the heavens. Alarmed, Bhagiratha prayed to Shiva that he break up Ganga's descent.

Ganga arrogantly fell on Shiva's head. But Shiva calmly trapped her in his hair and let her out in small streams. The touch of Shiva further sanctified Ganga.

As Ganga travelled to the nether-worlds, she created a different stream to remain on Earth to help purify unfortunate souls there. She is the only river to follow from all the three worlds – Swarga (heaven), Prithvi (Earth) and, Patala (netherworld or hell). Thus is called "Tripathagā" (one who travels the three worlds) in Sanskrit language.

*taken from online source