The Harvest Festival of Kerala, is one of the most popular one too. The harvest festival is the most popular festival of Kerala. The legend behind the festival goes back to the golden reign of the great, kind and mighty demon king Mahabali. This demon won over the kingdom of gods in war and Vishnu came to their aid. Lord Vishnu then disguised himself as a small Brahmin boy, Vamanan, and asked for three steps of land. The wish was granted and Vamanan then assumed the huge size and covered the whole land with his two steps and then asked the King for the place where he could put his third step.
The king to honor his word offered his head as the third step and
Vamanan pushed Mahabali into the abyss. However, he granted him a wish
that he could he could visit his kingdom and people on a particular day
once a year, the day which usually falls in the ten-day festivity of
this harvest season. A floral carpet called "Athappookkalam"
in front of houses, Carnivals, Boat Races, Dance, Music and Feast
consisting of a the traditional sweet dish of Kerala 'Payasam' on
plantain leaf characterize Onam.