Festivals in sacred sites of India, called melas are a vital part of the pilgrimage traditions of Hinduism. Celebrating a mythological event in the life of a deity or an auspicious astrological period, the melas attract enormous numbers of pilgrims from all over the world.
The greatest of these, is a riverside festival held four times every twelve years, rotating between Allahabad at the confluence of the Ganges, Yamuna and Saraswati rivers; Nasik on the Godavari River; Ujjain on the Shipra River and Haridwar on the Ganges River. Bathing in these rivers during the Kumbha Mela is considered an endeavor of great merit, cleansing both body and soul. The Allahabad and Haridwar festivals are routinely attended by five million or more pilgrims (13 million visited Allahabad in 1977, 18 million in 1989, and nearly 24 million in 2001) thus the Kumbha Mela is the largest and oldest religious gathering in the world.