Simhastha is ujjain's holy solemn bath. It is celebrated at the interval of twelve years when Sun is in the Aries and Jupiter is in the Leo. That is why the kumbh fair which is held at four places is knows as Simhastha in Ujjain. It starts with a holy bath in Solemn Shipra from the full moon of the first month of Hindu Calendar. It is celebrated for the whole month and ends with the bath one by one on different dates with the last one on the full moon day of second month of Hindu Calendar.
For this holy month celebrated in Ujjan, ten important conventional Yog are known. Ujjain is Situated on the western side of Madhya Pradesh near the river bank of Pavitra Kshipra. It is one of the most important and sanctum place of Indra.
The most important reason is self apparent of Lord Shiva in the form of Mahakal. From here only, Lord Shiva Mahakal devastated King Tripur and for this only he is also knows as Tripurari. Along with this Harsiddhi Shaktipeeth is present here as the elbow of Mata Sati was fallen here. Chappan Bhairav, Nav Narayan, 84 Mahadev and 64 Yogini are also present here.
According to primeval narration or say fiction, while churning of the sea was completed with the collabration of Lords and Devils, a pot full of nectar was also revealed. The lords were not ready to give the nectar to the devils. So Jayant, son of Indra, ran away with the por and was followed by the devils. The struggle lasted for twelve days and the drop of nectar fell on four places on the earth namely "Haridwar", "Prayag (Allahabad)", "Ujjain" and "Nasik". In the holy solemn remebrance of nectar in the holy Kshipra. A great feast known as Simhastha is celebrated every twelfth year.
As the struggle went for twelve days and one day is equal to one year, so is celebrated after every twelve years. Different planets are responsible for different holy feasts. In Ujjain, when Jupiter in Leo, Aries in Sun and Libra in Moon arries, is the time for Simhastha.
Ujjain has a very important place in the different cultural traditions. For eras, Mahakaleshwar temple and Holy Shipra has been a center of attraction for the different people to visit ujjain. During simhastha, lacs of people of different community temporarily stick here, which shows how the whole nation is bounded by the strength of some unseen inspiration.
Planning of simhastha is an ancient tradition. Many mythological tales are popularized in relation to it. The most famous tale is of churning of Sea.
When the lords and devils were struggling for the pot of nectar, it felt in the "Ganga", "Yamuna", "Godavari" and the "Kshipra" in the form of drops and these rivers became holy and the places become sanctum. The nectar pot was in the special custody of Sun, Moon and Jupitar. That is why this holy feast is celebrated when these star signs are in a unique conditions.