गङ्गावतरण Gangavataran literally translates to 'The Descent of Ganga', and shows Lord Shiva in all his glory.
In Hindu culture we have a proverb called "भागीरथी प्रयत्न Bhagirathi Pryatna," which means to an extraordinary effort or a monumental task, inspired by the multi-generational Ikshvaku lore of King Bhagiratha who is also an ancestor of Shri Ram. Bhagiratha was the king of Kosala, a kingdom in ancient India. To absolve his ancestors of their sins, Bhagiratha performed a rigid penance, on being told that only the water from Ganga can purify their sins. Pleased with his determination, Lord Brahma granted him his wish, and Ganga,on Brahma's orders, came gushing down, unaware of her power and surge. The gushing water threatened to destroy everything in it's path, and Brahma advised Bhagiratha to pray to Shiva for help. Lord Shiva came to the Earth's rescue by standing upright and directing Ganga's flow into his hair.