An estimated 30 million people visited the Maha Kumbh Mela on 10 February 2013 and an estimated 100 million are expected to visit the place during the festival spread over 55 days. Both (in a single day and over a specific period) are the largest peaceful human assemblies in the world. According to estimates, around 70 million people participated in the 45-day Ardh Kumbh Mela at Prayag in 2007. The Purna Kumbh Mela held in 2001 in Prayag was estimated to have attracted between 30 and 70 million people.The Maha Kumbh Mela, or Grand Pitcher Festival, takes place every 12 years in Northern India and sees millions of devotees bathe in the Ganges to purify their sins. The Kumbh is held at the confluence of the Ganges and Yamuna rivers, where Hindu scriptures say the gods spilt a drop of the elixir of immortality.
Kumbh Mela takes place every twelve years at one of four places: Allahabad, Haridwar, Ujjain and Nashik. The Mela in its different forms alternates between Prayag, Nashik, Ujjain and Haridwar every third year. The Ardh (half) Kumbh Mela is celebrated every six years at only two places, Haridwar and Prayag.
Kumbha Mela: Held at all four places.
Ardha Kumbha Mela: Held at Haridwar and Prayag, every 6 years.
Purna Kumbha Mela: Held only at Prayag every 12 years.
Maha Kumbha Mela: Held only at Prayag, every 144 years.
