Karthikai could possibly be called the South Indian equivalent for Diwali. While Diwali for us means Ganga-snanam (purifying bath), new clothes and of course, crackers, it is Karthikai for which all the lamps come out in full force... especially the earthen ones! The festival is celebrated over 3 days - the first day is called Bharani Deepam, the second is called Annamalai Deepam, and the third is Sarvalaya Deepam. The second is the main day, when a huge lamp is lit on the holy mountain of Thiruvannamalai, symbolising the form of Shiva as a never ending pillar of light (Yes, that's another long story, one I dont have time to write right now!).