It is said that before the time of humans - there was a massive samudra manthan (churning of the ocean) . This was carried out by the Gods on one side and the Demons on the other side. They combined their forces for a common goal - to unearth the greatest and most precious treasures from the depths of the ocean. The greatest of the great treasure of them all was - the Amrit kumbha (pot of immortality nectar). Both Demons and Gods wanted amrit which will make them immortal and hence invincible. A great battle ensued, and spread to the four big cities. These cities were Naasik, Ujjain, Haridwar and Prayag.
