Nataraja Temple, also referred to as the Chidambaram Nataraja temple or Thillai Nataraja temple, is a Hindu temple dedicated to Nataraja – Shiva as the lord of dance – in Chidambaram, Tamil Nadu, India.
The present temple was built in the 10th century when Chidambaram was the capital of the Chola dynasty, making it one of the oldest surviving active temple complexes in South India. After its 10th century consecration by the Cholas who considered Nataraja as their family deity, the temple has been damaged, repaired, renovated and expanded through the 2nd millennium. Most of the temple's surviving plan, architecture and structure is from the late 12th and early 13th centuries, with later additions in similar style.
The temple is one of the five elemental lingas in the Shaivism pilgrimage tradition, and considered the subtlest of all Shiva temples (Kovil) in Hinduism. It is also a site for performance arts, including the annual Natyanjali dance festival on Maha Shivaratri.
The Nataraja temple in Chidambaram is located in the southeastern Indian state of Tamil Nadu. It is about 5 km north of the Kollidam River (Kaveri), 15 km west from the coast of Bay of Bengal, and 220 km south of Chennai. The closest major airport is about 60 km north in Pondicherry. The Tamil Nadu State Transport Corporation and private companies operate services connecting it to major cities in the state. The site is linked to the Indian Railways with daily express trains to South Indian cities.
Chidambaram is a temple town, with the Nataraja complex spread over 40 acres within a nearly square courtyard in the center. Its side roads are aligned to the east-west, north-south axis. It has double walls around its periphery with gardens. It has had entrance gateways on all four sides.
Chidambara Ragasiyam/Rahasyam (Tamil for "secret of Chidambaram") is a Hindu belief that there is a secret message conveyed through the embossed figure near the shrine of Shiva in Chidambaram temple.

Since ancient times, it is believed that this is the place where Lord Shiva and Parvathi are present, but are invisible to the naked eyes of normal people. In the Chidambaram temple of Lord Nataraja, Chidambara Ragasiyam is hidden by a curtain (Maya). Darshan of Chidambara Ragasiyam is possible only when priests open the curtain (or Maya) for special poojas. People who are privileged to have a darshan of Chidambara Ragasiyam can merely see golden vilva leaves (Aegle Marmelos) signifying the presence of Lord Shiva and Parvathi in front of them. It is also believed that devout saints can see the Gods in their physical form, but no such cases have been officially reported.

The phrase "Chidambara Ragasiyam" really means something different. The pharse literally means a secret associated to Chidambaram - the place. Behind this is a real meaning to a secret. As described above there is a particular kind of curtain which when removed enables us viewing the secret. The real significance of doing so is that, when the curtain which is "maya" is removed one can see his real self. And the seeing of oneself removing the curtain of maya is viewing the secret. According to legend, "Chidambara Ragasiyam" will never be revealed as it is the secret relating to a particular person who sees it removing the screen of "maya". In the temple, when the poojas are performed and the screen is removed, one will be able to see the secret only when he applies this to his mind and soul.