A Hindu festival and assembly, held once every twelve years at four locations in India, at which pilgrims bathe in the waters of the Ganges and Jumna Rivers.Thus there is a Kumbh Mela every three years but the greatest is that staged in Allahabad....
I predict that this Kumbh Mela will outclass and completely overshadow the publicity and value of Harry Potter.
Origin
From Sanskrit, literally 'pitcher festival', from kumbh 'pitcher' + melā 'assembly'.