Onam is the grand festival of the people of Kerala. This annual event is a much-awaited one and on arrival it transforms the land and people into a jubilant mood.
As per the popular belief, the main reason for celebrating Onam is to mark the arrival of Mahabali, the king who once ruled Kerala, during the Onam days. Households and people gear up to welcome the magnanimous Mahabali, the king who was sent to the nether world by Vamana (the dwarf incarnation of Lord Vishnu).
During Onam, children, young and the aged with cheerful and joyous faces take part in activities like collecting flowers for making beautiful floral carpets; engage in games and entertainments.
The pinnacle of Onam festivities is of course the ona sadya (traditional vegetarian feast) especially on the Thiru Onam day.
Onam is also an occasion of plenty from an agrarian point of view. For the same reason it also takes the form of harvest festival.
As per the traditions of the Onam festival, it is believed that King Mahabali arrives every year during Onam, to see for himself and make sure that his subjects are still living without any hardships as it was during his days.