Photos:Kumbh Mela -- the world's biggest religious festival

India doesn't do things small, religious festivals included. 

Over 55 days from January 13, an estimated 100 million Hindu devotees will make their way to the Kumbh Mela religious celebration in Allahabad in the north Indian state of Uttar Pradesh.

The festival, which formally started at dawn on Monday morning, is held in honor of the Hindu mythological belief that when gods and demons fought over a kumbh (pitcher) of the nectar of immortality, a few drops fell in the cities of Allahabad, Haridwar, Nasik and Ujjain. These are the four places where the festival has been held for centuries.