Onam is the 10-day harvest festival of Kerala and is celebrated with much pomp and joy. Onam is marked in the month of Chingam, which falls between August and September, according to the Malayali calendar. The festivities honour Vamana, Lord Vishnu's avatar, and the return of the legendary and kind-hearted King Mahabali. Mahabali was also a great devotee of Lord Vishnu and one of the most generous kings, as described in the Hindu scriptures.
Onam celebrations begin with Atham. This is the day before Mahabali returns to his kingdom. Grand processions like the Athachamayam are held at the Vamanamoorthy Thirrikara Temple and throughout Kochi. As the days of the festivities pass, people continue to add layers of Pookalam, beginning with the base layer known as Athapoo.
