The place Nagoore is about 5 kms from Nagapattinam. The Raja Gopuram of the temple is of five tiers and a prakaram. The temple is dates back to some 2000 years.
Main Deity is Swayambu Lingam known as Naganadhar and his consort, known as Nagavalli Amman.
The place is known as Punnaga Vanam. Sthala vruksham is Punnai. Teertham here, known as Chandra Teertham.
In Tamil month of Vaigasi (May/ June) full moon day Sri Naganadhar emerged under the Punga Vruksham in presence of Lord Vishnu.
Brahma Indran, Chandran, Saptha Rishi, Durvasa Muni, Samudra Rajan, and a Brahmin named Rudhirasanman worshiped Sri Naganadha Swamy of this place..
To the inner prakaram, there is a separate sanctum with mandapam for Sri Raghu Bagawan. Inside the sanctum we see Sri Naga Valli, Sri Nagakanni Ambal samedha Sri Kanni Raghu Bhagwan.
Sthala purana says he was been worshiped by these persons in all four yugam. In Tamil month of Ani (June / July) full-moon day for ten days, as Brahmotsawam, Chandran worships Lord Siva and he was blessed.
In Tamil month of Masi (Feb/March) full-moon day for ten days as Brahmotsavam, Indra worshiped Lord Siva and was blessed by Sri Naganadhar.
A Brahmin known as Sambudattan with, his wife and son was living in forest. He was living in forest to penance. One day the small boy while playing in the forest happen to see the mating of Takkan (king of Serpents)with his wife. Takkan realized the boy has witnessed this action; due to his karma Takkan chased the boy. He was bitten and lost his life. In the mean time Brahmin’s wife was worried about the where about of his son. She asked her husband to go in search for the child.
When Sambudattan went in search of his son he found him dead. Brahmin with his superficial power came to know the cause of death. He cursed Takkan to abandon from Naga Lokha, and he will be alone in the forest on earth. Takkan will loose his intelegence and power. Takkan was worried and he prayed to Brahmin, for solution to get out of the curse. Brahmin said after a period 1000 years, when Takkan meets his father Kasyap, he will be out of his curse.Takkan (Naga Raja) worshiped Lord Siva here in Tamil month of Masi (Feb/ March)on Sivarathri day.
On Sivarathri day Lord Siva is worshiped four times. Thakkan performed first time pooja in Sri Nagandha swamy temple of Vilvaranya kshetram at kumbakonam, Second Kala pooja at Thiru Nageswarm temple Sri Nagandhar of Champakranya Kshetram, third kala pooja at Thirupampurm temple Sri Nagandhar of Vanni Vanam, and finally fourth kala Pooja at Sri Nganadha Swamy of Punnaga Vanam. He got rid of his curse and attained Mukthy at the feet of Sri Naganadha swamy of Punnaga Vanam, Thiru Nagoore.
Sthala purana says one who has Raghu Dosha, they can worship Kanni Raghu of this temple. By worshiping Naganaddhar here one is blessed with Gyanam. This is a prihara sthalam for Raghu.