This video from Religion & Ethics NewsWeekly shows Hindu pilgrims from India and beyond gathering to celebrate Kumbh Mela, which involves the ritual of purification by bathing in four sacred rivers. The pilgrims in the video walk hundreds of miles to bathe in the River Ganges. Kumbh Mela is based upon ancient Hindu mythology and occurs four times during a twelve year cycle. Hinduism, considered to be the oldest religious tradition in the world, consists of a complex combination of theology, philosophy, culture and rituals that vary depending upon region.