As per the mythology the reason behind Kumbh mela was a story of samudra manthan (churning of ocean). Samudra manthan was done by gods and demons to achieve Amrut (drink of immortality). While churning the divine physician Dhanvantari emerged from the ocean holding Amrut Kumbh. He flew away with the pot of Amrut to prevent the demons from seizing it. The battle between gods and demons took place for 12 days and 12 nights which are 12 years for human beings. While carrying Amrut Kumbh drops of Amrut spills at four places namely Haridwar, Prayag, Ujjain and Trambakeshwar. Moon protected the amrut from spilling, Sun protected the Kumbh from cracking and Jupiter protected it from demons. Hence whenever Sun, Moon and Jupiter enters Aquarius or Kumbh (Zodiac sign) Kumbha Mela occurs. And Temples of Gods have been erected at the same places near Kumbh Mela.