Mahamaham is a Hindu Kumb Mela festival celebrated every 12 years in the temple-town of Kumbakonam in Tamil Nadu, India. Hindus consider taking a holy dip at the Mahamaham tank on the day of Mahamaham as sacred. The last Mahamaham was celebrated on March 6, 2004, with people from various places taking the holy dip in the Mahamaham tank.

The festival is celebrated at an interval of around eleven to twelve years. The festival takes place at a particular time as determined by astrological position: during the full moon of the Tamil month of Thai (February-March) when the conjunction of the moon with the lunar asterism (Magha Nakshatra) and when Jupiter is in the constellation of Leo.

The festival lasts for nine days. During this festival, thousands of Hindu devotees come to Kumbakonam, and take bath in a tank named Mahamaham tank. Some of them instead of taking bath in the tank, sprinkle water from the tank on their bodies. It is believed that taking bath or sprinkling water of the tank on the bodies cleanses all the sins.

On the occasion of the festival, a metal image of the deities of the main temple of Kumbakonam is carried on palanquis or chariots and taken around the different streets of the town.

During the third Pralaya ( Deluge) , the seeds of next cycle of creation were stored in an holy kalash. On the night of deluge Yogi Kakabhusanda directed the pot filled with amrit ( necter ) be sealed and its neck tied with a string. When the waters started subsiding , the pot which was floating finally touched the earth at the spot where present day Kumbhakonam is situated. The pot tilted , the cord snapped , the nectar flowed out and formed a pool. This legendary pool is present day's Mahamaham tank. The pot (Kumbha) tilted at an angle (kona) and hence it was named Kumbhakonam.

There is an oft quoted popular saying in Sanskrit noting Kumbakonam as even as more sacred than Varanasi(Kasi). A sin committed at some ordinary place is washed off by a visit to a holy place, sin done in a sacred spot is washed off by going on a pilgrimage to Varanasi(Kasi). If one dares to commit a sin in that sacred city too, that sin is wiped off at Kumbakonam and any sinful act done at Kumbakonam is atoned for there itself.

The next Mahamaham will be celebrated in the year 2016.

The 20 theerthams in the Mahaamaham tank

1. Indra Theertham – provides moksham
2. Agni Theertham – rids Brahmahatthi dosham
3. Yama Theertham – rids fear of death
4. Nruthi Theertham – rids from fear of evil spirits
5. Varuna Theertham – provides long life
6. Vaayu Theertham – rids diseases
7. Gubera Theertham – provides prosperity
8. Isaana Theertham – moksham (to reach Lord Siva’s feet)
9. Brahma Theertham – pacifies ancestors
10. Gangai Theertham – provides Kailasa padavi
11. Yamuna Theertham – provides wealth
12. Godavari Theertham – fulfills wishes 13. Narmada Theertham – provides physical strength
14. Saraswathi Theertham – provides Gnaanam (enlightenment)
15. Cauveri Theertham – provides knowledge
16. Kumari Theertham – blessings to pets
17. Payodini Theertham – provides joy
18. Sarayu Theertham – removes mental strain
19. Arubathaaru(66)kodi Theertham – removes grief & provides hapiness
20. Deva Theertham / Naaga Theertham – rids of all sins & provides rids of Kaala Sarpa dosham

It is believed that taking dip or sprinkling water of the tank on the bodies cleanses all the sins.The Mahamaham Tank has four streets alongs its four banks. It is constructed with steps on the sides for people to easily access the tank and take dips. There are 16 Mandapas ( Gopuram Towers) around the corners and sides of the tank.These towers are considered to be forms of lord Shiva ( The Hindu God)