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 CE when the shilpa shastras, the canonical texts of temple architecture, were written. Estimates of the age of the brick shrine range from 1700 to 2200 years. Archaeologists believe that the brick shrine was destroyed either by a cyclone or a tsunami which took place 2,200 years ago. The Pallavas built a granite temple on the brick foundation in the 8th century CE, which also was likely to have been destroyed by a tsunami. Archaeologists believe that the second tsunami must have occurred in the 13th century CE as the latest inscriptions which speak of the shrine have been dated to 1215. Historical background Although the city of Mahabalipuram was constructed by the Pallava king Narasimhavarman I in the 7th century CE, there is evidence that a small port might have functioned at the site even earlier. Megalithic burial urns dating to the very dawn of the Christian era have been discovered near Mahabalipuram. The Sangam age poem Perumpāṇāṟṟuppaṭai describes a port called Nirppeyyaru which some scholars identify with the present-day Mahabalipuram. Sadras near Mahabalipuram has been identified as the site of the port of Sopatma mentioned in the Periplus of the Erythraean Sea. Inscriptions There are many rock inscriptions near the temple. The discovery of three granite pillars with inscriptions of grants made to the shrine led to the discovery of the temple itself. While one pillar contains an inscription recording the donation of ten kazhanchus (small balls) of gold by one Kirarpiriyan of Mahabalipuram in 858, another records the donation of 16 kazhanchus of gold in 813 for the maintenance of a lamp by a Brahmin woman named Vasanthanar. The third pillar has an inscription by Raja Raja Chola I. Apart from these, there are five other pillars with inscriptions by the Pallava kings Dantivarman I, Nandivarman III and Kambavarman, the Rashtrakuta king Krishna III and the Chola king Rajendra Chola III. Architecture The temple is dedicated to the Tamil deity Murugan and faces north. The garbhagriha or sanctum