Kanchipuram Sree Nilathingal Thundatthan Temple is the One and Only Divyadesams where the poojas are being done by the Saivite Preists. The temple is located inside the Siva Temple - Ekambareswarar Temple.
When Paarvathi was doing Tapas beneath a mango tree, Lord Shiva wanted to test the strength of her tapas. So, he fired the Mango tree. At that time, Paarvathi seeked the help of Vaamanar.
After hearing the help voice of Paarvathi, Sri Vaamanar with four hands with Sangu in one hand and Chakram on the other, took out the Chandran (Moon) from the head of Lord Shivan and with the cool rays out of it he made the fire cool and made the Mango tree grow once again.After this, Paarvathi went back to do the Tapas.
But, Lord Shivan wanted once again to test her and sent Ganga, the river. When she came very fast to destroy the tapas of Paarvathi, Paarvathi explained her that both of them are sisters. Inspite of hearing this, Ganga river doesnt want to stop and tried to destroy her and her tapas. At that time, Parvathi made a Shiva Lingam out of sand and hugged it towards her.
At that time, both Shiva and Paarvathi got mixed to each other. This is the Sthala puranam of this temple.Since, to help Paarvathi, Sriman Narayanan took the Chandran (Moon) from Lord Shiva's head to prevent the Lingam done by sand from Ganga river, the Perumal is called as "Nila thingal thundathan" and so the sthalam is called as "Thiru Nilathingal Thundam".
This Divyadesam is found inside Ekambareswar temple. Since, this temple is taken care by Siva Aacharyas, the poojas for Sri Vishnu is done by a Sivaachariyar only.
Lord Maha Vishnu took the form of Tortoise (Koorma Avatara) to the hold the Meru Mount used as the stick (Mathu in Tamil) to churn the milk ocean. Serpent Vasuki was used as the rope. Vasuki, exhausted during this exercise, split its venom which fell on the Tortoise Vishnu under the milk ocean blackening His skin originally alluring pale blue.
Treatments were of no avail. Lord Brahmma suggested that worshipping Lord Shiva will remove the blackness and restore His original shade. Perumal performed penance on Lord Shiva, who granted darshan. Crescent Moon on the head of Lord Shiva spread his rays on Perumal. Black disappeared. He recovered His own alluring blue shining better than before.
Lord EkambareswararTemple was built on the background of this story. As Perumal got back His skin colour as before through rays of Moon, He is praised as Nila Thunda-crescent moon-Perumal.
The shrine is in the Easanya corner ? north east- of the temple. This is a temple in a temple ? Vishnu temple in Shiva temple. This is praised as one of the 108 Divya Desas of Lord Vishnu.
Moolavar - Nilathingal Thundathan, Cahndrasoodan
Thayar - Ner Oruvar Illavalli Nachiyar
Blessing Pose - Standing Posture Facing West
Vimanam - Purushasuktha Vimanam
Theertham - Chandra Pushkarini
Kshetram - Sathyavradha Kshetram