Legend has it that the Thiruvotriyur Temple is the oldest and the Thiruvannamalai is equally ancient.
Concrete historical evidence has been unearthed by the archeologists of a Temple of Lord Murugan in Saluvankuppam,Tamil Nadu.
The Subrahmanya Temple at Saluvankuppam, Tamil Nadu, is a shrine dedicated to the Hindu deity Murugan. Archaeologists believe that the shrine, unearthed in 2005, consists of two layers: a brick temple constructed during the Sangam period (the 3rd century BC to the 3rd century AD) and a granite Pallava temple dating from the 8th century AD and constructed on top of the brick shrine. The Archaeological Survey of India (ASI) team which conducted the excavation believe that brick temple could be the oldest of its kind to be discovered in Tamil Nadu. However, noted Indian archaeologist R. Nagaswamy is critical of this claim owing to lack of references to the shrine in the popular literature of the period.
The temple was discovered by a team of archaeologists from the ASI based on clues found in a rock inscription left exposed by the 2004 Indian Ocean tsunami. Initially, excavations revealed an 8th-century Pallava-era shrine. Further excavations revealed that the 8th-century shrine had been built on the brick foundation of an earlier shrine. The brick shrine has been dated to the Sangam period.’
The temple faces north, unlike most Hindu temples. Artefacts from two phases, the Sangam phase as well as the Pallava phase, have been found. The temple is Tamil Nadu’s oldest shrine to Murugan. It is also believed to be one of only two pre-Pallava temples to be discovered in the state, the other being the Veetrirundha Perumal Temple at Veppathur.
The Sangam period extended from roughly 350 BC to 300 AD
After the 2004 Indian Ocean tsunami had subsided, archaeologists discovered rock inscriptions which had been exposed by the tsunamiwaves close to the hamlet of Saluvankuppam, near the UNESCO-designated World Heritage Site of Mahabalipuram. The inscriptions by the Rashtrakuta king Krishna III and the Chola kings Parantaka I and Kulothunga Chola I spoke of a Subrahmanya Temple at Thiruvizhchil (the present day Saluvanakuppam). S. Rajavelu, epigraphist with the Archaeological Survey of India (ASI), identified a nearby mound as the site of the temple. In 2005, archaeologists unearthed an 8th-century Pallava temple under the mound. G. Thirumoorthy, ASI Assistant Archaeologist, believed that the shrine could be the oldest Subrahmanya temple to be excavated in Tamil Nadu. There were speculations on whether the temple could be one of the “Seven Pagodas”
However, further excavations revealed that the 8th-century temple was constructed over the remains of an older brick temple. According to Thirumoorthy, the garbhagriha or sanctum sanctorum of the brick temple was filled with sand and covered with granite slabs upon which the newer temple was constructed. Sathyamurthy, Superintendent, ASI Chennai Circle, said that the brick temple could be dated to the Sangam period as the shrine faced north unlike modern temples which face either east or west. This proved conclusively that the temple was constructed before the 6th or 7th century AD when the shilpa shastras, the canonical texts of temple architecture, were written. Estimates of the age of the brick shrine range from 1700to 2200 years.