The legend goes this way; King Mahabali ruled the southern dynasty those days and was very famous for his wise, just and benevolent nature. He was egoistic and proud of his popularity and richness. At the same time, Lord Vishnu is perturbed due to Mahabali's fame. Thus, to deplete him off this popularity and to teach him a lesson, Vamana, the fifth avatar (incarnation) of Lord Vishnu, disguised as a Brahmin, and requested him three steps of land. Two steps of Him covered whole earth and patal (lower world). King Mahabali offered his head for the third step to be placed and thus King Mahabali was pushed down to 'patalam'.
Lord Vishnu was very pleased with the determination with which King Mahabali tried to fulfill his promise and allowed him to visit his country and people once in a year. Thus on the day of 'Onam' it is believed that the King Mahabali visits his country to see its prosperity and share the joy and spirit with the inhabitants.
We mark the festival from the day of 'attam'. The idol of vamana is worshipped during these days. The people start decorating their houses with flowers designed in various patterns known as 'pookalam'. They welcome their Lord with onnapattukal (songs meant for Onam), many games such as vallam kalli (boat race), kaduva kali (tiger dance) etc. Cultural dances like thiruvathira, mohiniyattam etc are organized by social organisation to grace the occasion.
The most important days of 'Onam' are Uthradam & Thiruvonam. Dressed in new traditional clothes, people goes to temple and await the come back of their Lord, followed by a grand feast including special delicacies like payasam, chips made up of bananas, achaars, pappadam, aviyal, many types of vegetable preparations etc. particularly served on banana leaves.
Onam is a kind of assembly at the 'tharavad' home, for the families who stay out of Kerala and long throughout the year to get back to their own land to be with their loved ones.
'Onam' is also marked as a tourist week in kerala. Tourist flock this state and participates in flower arrangements, boat race etc with great enthusiasm and carries with them an inexplicable memories of this festival.
Onam is a best example of religious harmony and unity among the people of all castes and religions.
