Govardhan Puja, also called Annakut...

Diwali the most important and colorful festival also the Festival of Light.
Govardhan Puja, also called Annakut (meaning a heap of grain) is celebrated as the day Krishna defeated Indra. Lord Krishna taught people to worship nature, as mountains bring rains to earth and to stop worshiping the God of Rains, Lord Indra. 
His was the message that we should take care of our nature.
The puja performed on the fourth day of Diwali is called the Govardhan Puja. The origin of this day goes back to the Dwapara Yuga, and to Lord Krishna. According to legends, 
he lifted mount Govardhan on this day and hence the day is dedicated to the worshiping the mountain.
Annakoot is also celebrated on the fourth day in observance of the episode of Sri Krishna's childhood, in which He gave protection to the cowherd clan of Vrindavan from the wrath of Indra and humbled Indra in that process. Annakut, also known as Nutan Varsh or Bestu Varsh, is the New Year’s Day in Gujarat. The first day in Gujarati Calendar is the day after Diwali  Kartik sud 1.
The name ' Annakut '  means  'Anna' meaning food and 'kut', mountain.
For Annakut a mountain of food is decorated symbolizing Govardhan mountain said to be lifted by Lord Krishna to save the people from the wrath of Lord Indra, the God of rain.
In Maharashtra it is celebrated as Padva or BaliPratipada. 
In Gujarat, it is celebrated as New Year.
This worship has carried on from 5000 years ago to the 21st Century.
According to the Shrimad Bhagavatam, "After lifting the huge Shri Govardhan Parvat (mountain) for seven continuous days prior to Diwali, the Lord put it back on earth & asked the citizens to worship the mountain. Bhagwan Shri Krishanji then appeared in two forms, one as the Shri Govardhan mountain itself, and the second in His human form, so that his devotees could offer food and prayers to Him.
So varieties of delicious sweets and 56 different kinds of bhog (offerings of food) were ceremoniously raised in the form of a mountain before Lord Krishna.
On this devotees offer their gratitude to Lord Krishna for his blessings in making their lives complete.
Annakut is thus one of the most auspicious days of the Hindu year.
“Earth, water, fire, air, ether, mind,
intelligence and false ego  all together
these eight constitute My separated material energies.
(Bhagvad Gita)