Karthigai Deeepam is the festival of lights in South India, especially in Tamil Nadu and Kerala. In Tamil Nadu, it is observed on the full moon day in the month of Karthigai (November-December). In Kerala, the festival is known as Thrikartika or Kartika Vilaku and is held in the month of Vrichikam (November – December). In 2007, Karthigai Deepam and Thrikartika is on November 24. Talk about Karthigai Deepam and the picture that comes to mind is that of rows and rows of lamps or diyas. On this day, every Hindu home will light traditional Vilaku (diyas) in the evening. Locally, these lamps are known as ‘agal vilakkus.’ The lighted lamp is an auspicious symbol and it is believed to usher in prosperity and joy. The most famous Karthigai Deepam in Tamil Nadu is held at Tiruvannamalai.