Tamil Nadu's Festival of Lights; beacon lit atop Tiruvannamalai hill

Karthigai Deepam is the ancient Tamil festival of lights, celebrated when the full moon of the Tamil month of Karthigai coincides with the Krittika (Karthigai) nakshatra; in 2026 it falls on 24 November. It is mentioned in Sangam literature and is among the oldest festivals of Tamil Nadu. Its central legend is that of the Lingodbhava: when Brahma and Vishnu argued over who was greater, Shiva appeared between them as an endless column of fire. Vishnu, as a boar, dug down to find its base and Brahma, as a swan, flew up to find its top; neither succeeded, and Shiva revealed himself as the infinite. At Tiruvannamalai, where the hill of Arunachala itself is revered as that column of fire, the ten-day Karthigai Brahmotsavam ends with the Bharani Deepam lit in the temple before dawn, and at dusk the Maha Deepam — a giant cauldron of ghee with a huge wick — is lit on the 2,668-foot summit, visible for miles, as lakhs chant 'Annamalaiyarukku Arohara'. The day also honours Murugan, who was raised by the six Krittika maidens. Every Tamil home lights rows of clay lamps (agal vilakku) at the doorstep, in the courtyard and on the walls, and prepares pori urundai, appam and adai.

Many fast during the day and eat after the lamps are lit.