This is one of the oldest and biggest temples in India; dedicated to Lord Shiva. The Shiva Linga here represents Agni or Fire among the five elements.
The Lord Shiva here is known as Lingodbhava Murthy. There is a legend behind this. One day, Lord Vishnu and Lord Brahma quarreled on the question of who is supreme among them.
To solve the dispute, Lord Shiva intervened. He announced a small competition among the two. Whoever finds the upper or bottom of the Shiva Linga first, becomes the winner; he will be considered as supreme.
Both of them agreed. Lord Vishnu took the form of a boar and started digging the soil to find the bottom of the Shiva Linga and Lord Brahma became a swan and began to fly upwards to find the top of the Shiva Linga. They tried to reach their target for many years, but in vain. So, Lord Shiva appeared before them by bursting out of the Shivalinga in the form of an agnigola or fire ball.
He declared that the question of supremacy is meaningless, so is the effort to find the end of the Shiva Linga. Both of them (Lord Vishnu and Lord Brahma) were created out of his divine desire.
The Shiva Linga of this temple is believed to be the Linga out of which Lord Shiva appeared as a fireball.
The earliest literary reference on this temple can be seen in Sangam literature. The archeological evidence goes even further.
The present structure goes back to the Chola period, that is 9nth century AD. From there on, many additions and alterations were made by various dynasties like Vijayanagara, Hoysala and Nayykkars.
The temple was a very important center of Saivaite worship. All most all Saivaite saints had visited the temple and praised the Lord here. It also attracted many Siddhas and Yogis like Sri Arunagirinathar and Sri.Manikkavachar. Sri.RamanaMaharshi being the latest among them.
The temple celebrates many festivals throughout the year. The Karthikai Deepam festival in November-December attracts the largest crowd. On this day, there is a procession carrying the idols of Lord Shiva and Goddess Parvati along with all the attendant deities of the temple. In the evening, there is a Jyothi( flame) Darshan on the nearby Annamalai hill. The darshan of this Jyothi is considered holy. Large crowd attend the chariot procession and the Jyothi. The number of footfalls on this occasion is said to be more than that of the Brahmotsav festival at Tirupati.
Moreover, each occurrence of full moon is a festival itself. On this day, many devotees circumvent the Annamalai hill by foot (about 15 kilometers in length). The hill is believed to be the representation of Lord Shiva himself.
The vast temple tank known as Shivaganga tank is considered holy.
Tiruvannamalai is 103 kilometers from Pondicherry and 187 kilometers from Chennai- the state capital.