Nageswaran Temple otherwise known as “Koothandavar Kovil”.Chola dynasty constructed this temple during the 12th century. This temple stands as a great marvel of Chola’s architecture, building technology.The design and orientation are structured in such a way that it allows the sun rays inside the temple only during the month of Chithirai.The Karuvarai of Nageswaran temple has similarity with that of Sarangapani temple, Swamy’s it is made in the form of a chariot.The temple consists of two Gopurams in the eastern and western directions. NageswSwamy is the main deity of the temple Nageswaran. The deity is Linga ( a form of God Shiva). The main deity resides into the charriot mandapam. The goddess of the nageswarar swamy is Periyanayagi Amman.
Divine serpent Adisesha was bearing the whole weight of earth. As the weight grew due to the sins committed by the wicked, he could not excess weight and felt exhausted. He visited Mount Kailash and begged Lord Shiva to bless him with the adequate energy needed to do his job. Lord promised him the energy to hold the earth with a single head (Adiseaha has 1000 heads). Adiseaha, with the blessings of Lord Shiva came to this part of Kumbakonam where one leaf of Vilwa fell from the nectar pot. He installed a Linga here and worshipped the Lord. As Nagaraja the king of snakes worshipped the Lord here, He is praised as Nageswarar. The place where the Vilwa fell from the nectar pot floating through floods, was called Vilwa Vanam. Lord is also praised as Vilwa Vanesar, Padala Beeja Nathar, Madanthai Bagar and Selva Piran.