Onam is an ancient festival which still survives in modern times. Kerala's rice harvest festival and the festival of rain flowers, which fall on the Malayalam month of Chingam, celebrates the Asura King Mahabali's annual visit from Patala

The most beautiful moments in onam is we are celebrate all relegion.this festival not seperate only for hindhu.This is kerala culture festival so we celebrate all over in kerala, including christain,muslim etc all relegions are celebrate only one festival in kerala that's onam.

Onam is colourfull festival, we celebrate onam in most beautiful ways

First:
Intricately decorated Pookalam(the image is above)

Second:
Thiruvathira Kali during Onam in Kerala

Third:
A typical onam sadya

And Finally ONAM song(this is the most beautiful moments):
Maveli nadu vaneedum kalam,
manusharellarum onnupole
amodhathode vasikkum kalam
apathangarkkumottillathanum
kallavum illa chathiyumilla
ellolamilla polivachanam
kallapparayum cherunazhiyum
kallatharangal mattonnumilla
adhikal vyadhikalonnumilla
balamaranangal kelppanilla................

Some onam image are above......