Shankara Narayana

Once Parvathi had a doubt as to who was greater – Shiva or Vishnu. She approached Shiva with this question, and Shiva asked her to go to South India and mediate on the Lord and would find out herself. Goddess Parvathi came down to and performed penance during the month of ‘Aadi’, popularly known as ‘Aadi Tapas’. She found the Lord as ‘Shankara Narayana’ – right hand side being Lord Shiva and the hand side being Lord Narayana, thus telling her that both were one and  same.

http://en.wikipedia.org/wiki/Shankaranarayana 

https://en.wikipedia.org/wiki/Sankaranayinarkoil

One of the seven holy places created by Maharshi Parshuram in karnataka
http://www.karnatakaholidays.com/shankaranarayana.php

 Kerala
http://www.vaikhari.org/shankaranarayana.html

Family Diety of Panchagrama Brahmins
http://en.wikipedia.org/wiki/Panchagrama_Brahmins
Mutt
http://wikimapia.org/1207240/Yoga-Narasimha-Temple-Mutt-Tirthamuttur