The Kumbh Mela is a Hindu pilgrimage which takes place on the banks of sacred rivers where pilgrims gather to take a dip in the holy waters. Four melas are traditionally recognized as Kumbh Melas which are as follows:

1. Prayagraj Kumbh Mela at the Triveni Sangam (confluence), the meeting point of the Ganga, Yamuna and the mythical Saraswati in Prayagraj (Allahabad), Uttar Pradesh
2. Haridwar Kumbh Mela on the banks of the Ganga at Haridwar, Uttarakhand
3. Nashik-Trimbakeshwar Simhasta on the banks of the Godavari at Nashik, Maharashtra
4. Ujjain Simhasta on the banks of the Shipra at Ujjain, Madhya Pradesh.

Following an overall cycle of 12 years, these melas are held on rotation basis at these sacred sites. During auspicious days, pilgrims gather at these places to take ritual baths which are believed to cleanse a person of all their sins and deliver them from the cycle and birth and death.

Besides these melas which are also called the purna (full) Kumbh, the ardha (half) Kumbh Mela is held every six years at Haridwar and Prayag (Allahabad) while the maha (great) Kumbh Mela is celebrated at Prayag (Allahabad) every 144 years on the completion of twelve Purna Kumbh Melas.

The etymology of the term Kumbh is associated with the immortal pot of nectar or amrita from the samudra manthan (ocean-churning) episode mentioned in various texts like the Bhagavata Purana, the Mahabharata and the Vishnu Purana. The devas (demigods) and asuras (demons) are said to have agreed to work together to produce amrita. They assembled on the shore of the ocean of milk that lay in the celestial realm of Hindu cosmology to churn the nectar of immortality. In the process of churning the ocean, poison was released which terrified the devatas and demons. The gods approached Shiva for help, who then consumed the poison in order to save the three worlds. His throat turned blue in the process due to which he came to be known as Neelakantha (blue throat).

The devas closed the kumbh (pot) of immortality nectar and entrusted it to four deities - Brahaspati, Surya, Shani and Chandra- after which a chase is said to have ensued between the devas and the asuras. The demons chased the gods for many days during which time drops of amrita landed on four places- Prayagraj, Haridwar, Ujjain and Nashik. On account of this event these places became major pilgrimage sites for the Hindus. The fight between the devas and asuras is said to have lasted for twelve divine days equivalent to twelve years in human time. Hence, the Kumbh Mela is said to be celebrated once in twelve years to commemorate this battle between the gods and demons for amrita.