Kovur Sri Sundareswarar Temple is a famous Hindu and famous as one of the Navagraha Sthalam for Planet Mercury. This illustrious temple is dedicated to Lord Shiva and situated in Chennai at Kovur. This ancient temple is very huge and built by King Kulothunga Chola in 7th century. The temple is well-known as the Navagraha temple of Thondai Mandalam. Inside the main premise, the Sthala Vruksham Maha Vilvam tree is a rare and an old tree in which each stalk of Maha Vilvam has 27 leaves. A Saint Sri Thyagaraja who was a carnatic music composer sang 5 traditional songs called collectively- Kovur Pancharatnam about this holy place. This Shiva place is established in 965 and the presiding idol of the temple is Sundareswarar, who is famed as a form (incarnation) of Shiva and Goddess Soundarambikai.
MahaShivratri is celebrated with a great show and pomp annually to pay homage to Shiva. A single darshan of Sundareswarar on this auspicious day is considered more than the Darshan of other deities dispersed in other parts of India. People also gather to commemorate various other occasions such as- Shrawan Maas, Deepawali and Holi with a great zeal. Most of the offerings at the this sacred temple are distributed to poor and poverty-strikens.