Kumbh Mela is a major pilgrimage in Hinduism, celebrated in a cycle of 12 years, to celebrate every revolution Brihaspati (Jupiter) completes. The mela takes place at four river-bank pilgrimage sites- Prayagraj, Haridwar, Nashik and Ujjain. It is marked by a ritual dip in the waters, which devotees believe is a means to atonement for past mistakes, and that it cleanses them of their sins. Kumbh Mela is traditionally credited to the 8th-century saint Adi Shankara, as part of his efforts to start major Hindu gatherings for philosophical discussions and debates across the Indian subcontinent. However, there is no evidence of mass pilgrimages, prior to the 19th century.