During the Karthigai Deepam celebrations, the lighting of the Mahadeepam on Arunachala Hill is the spiritual highlight.The sight of the sacred flame from the surrounding town is considered highly auspicious by devotees.Karthigai Deepam is the signature festival of Tiruvannamalai, bringing together the temple, Arunachala Hill, the sacred fire of Shiva and the ancient tradition of Girivalam.