Thiruparkadal

Thiruparkadal (Tamil: திருப் பாற்கடல்) has a rarest among the rare, temple in the country, where Thirumal stands on God Siva to show the world, the amalgamation of Vaishnavism with Saivism and to enlight both of them are one and the same.
Salient Features.
Thiruparkadal village, known as Karapuram in ancient times, is a scenic fertile area surrounded by greenish fields and is the site of two Sivan temples and two Vishnu temples. This is the location where Lord Vishnu lay on Adisheshan to prevent the gushing Sarasvathi river from disrupting and destroying the "yagha" performed by Lord Brahma to seek the grace of Thirumal at Kanchipuram.
Vishnu on Palar River Bed.
Lord Vishnu lays on Adisheshan to prevent the Saraswathi river called 'Vegavathi' at three places. One at Pallikonda [Uthara Ranganathar] near Vellore, Then at Tiruparkadal, And finally at Kanchipuram where the temple is called Tiruvekka where the deity holds the name 'Yathothrakaari'.
Vishnu Stands on Sivan.
It is an interesting part. It is said that one Vaishnava Maharishi named Pundareegar visited Thiruparkadal to have Darshan of Sri Ranganatha swami. But he found a Siva lingam into the sanctum Sanctorum named Sree Doseswarar instead of Vishnu, by seeing this he was disappointed and returned.
Lord Vishnu wanted to fulfill the aspiration of the Vaishnava devotee, and transformed himself as an old vaishnavite, and enquired Maharishi. Maharishi shared his disappointment with old vaishnavite. But the old man insists that it is only Thirumal Sannathi and asked the Maharishi to visit the temple once again, and accompanied the Maharishi to temple and then disappeared. Maharishi walked right into inner Sanctum of the temple and seen the Thirumal with Abhaya Mutra standing on Siva lingam. This was on Ekadasi day, and from on that day the presiding deity is called as Sri Prasanna Venkatesa Perumal. This temple is hailed as the place to show the devotees that Siva and Hari are one and the same. Every year on Vaigunda Ekadasi day, a number of devotees visit this temple. Another vaishnavite temple called as Sri Ranganathar temple is situated at the side of the Prasanna Venkatesa perumal temple.
Temple Architecture and Significance.
The Rajagopuram of Sri Prasanna Venkatesa Perumal temple is in dilapidated state. Next to it is, Kodimaram, Pundareega Pushkarani and an altar, small mandapam and Maharishi Gopuram welcomes us. There is another mandapam in the entrance of Sanctum Sanctorum which has also Shrines for Thumbikkai Azhwar, Nammalwar, Madurakavi Azhwar, Thirumangai Azhwar, and Boothathazhar.
Inside inner sanctum, the presiding deity lord venkatesaperumal stands on Avudaiyar (Siva lingam) with Abhaya Mutra. It is a most memorable and pleasurable moment to have Darshan of Both Hari and Siva. There are carvings of Krishna Devarayar, Dhalavan Naicken, Rani Mangammal, Aranganayagam and Aranganayaki, all in praying pose.
The Sprawling temple renovated by the king of Vijayanagar. Krishna Daverayar has also shrines for Alamelu mangai thayar, Anjaneyar, Karudazhwar, Desikar, Rukmani, Sathyabhama, Thirukkachi nimbi adigal. This temple was patronized by Krishna Daverayar, and hence inside the Sactum, there is an idol of him.
How to reach Thiuparkadal.
Thiruparkadal is 2.5 km from Kaveripakkam in Chennai-Bangalore Highway Road, 99 km from Chennai, 40 km Vellore and 28 km from Kanchipuram.