The Annamalaiyar Temple is the most prominent landmark of Tiruvannamalai. The temple complex covers an area of 10 ha (25 acres), and is one of the largest temples in India. It houses four gateway towers known as gopurams. The tallest is the eastern tower, with 11 stories and a height of 66 m (217 ft), making it one of the tallest temple towers in India. The temple has numerous shrines, with those of Annamalaiyar and Unnamulai Amman being the most prominent. The temple complex houses many halls; the most notable is the thousand-pillared hall built during the Vijayanagar period.
The Annamalaiyar temple is one of the Pancha Bhoota Stalas, or five Shiva temples, with each a manifestation of a natural element: land, water, air, sky or fire. In Annamalaiyar temple, Shiva is said to have manifested himself as a massive column of fire, whose crown and feet could not be found by the Hindu gods, Brahma and Vishnu. Aathara Stala are Shiva temples which are considered to be personifications of the Tantric chakras of human anatomy. The Annamalaiyar temple is called the Manipooraga stalam, and is associated with the Manipooraga chakra. The temple is revered in Tevaram, the Tamil Saiva canon and classified as Paadal Petra Sthalam, one of the 276 temples that find mention in the Saiva canon.
The most important festival of the Annamalaiyar temple is celebrated during the Tamil month of Karthikai, between November and December, concluding with the celebration of Karthikai Deepam. A huge lamp is lit in a cauldron, containing three tons of ghee, at the top of the Annamalai hills during the Deepam. To mark the occasion, the festival deity of Annamalaiyar circumambulates the mountain. Inscriptions indicate that the festival was celebrated as early as the Chola period (from 850 CE to 1280 CE) and was expanded to ten days in the twentieth century.
Every full moon, tens of thousands of pilgrims worship Annamalaiyar by circumambulating the Annamalai hill barefoot. The
