Tank

The water in the Kumbakkonam Tank is a mixture of water from the Sacred 

http://kuinformation.blogspot.com/search/label/NavaKanniyar

 The water has been held as sacred and holy for thousands and thousands of year through their very means of creation and by prayers and rituals of people since their beginnings.

http://en.wikipedia.org/wiki/Mahamaham_tank,_Kumbakonam
http://www.youtube.com/results?search_query=kumbakonam+tank

The sixteen Siva lingams in the sixteen mandapams around the Mahamaham tank

1. Shri Brahmatheerthaeswarar 
2. Shri Mugunthaeswarar 
3. Shri Thaneshwarar 
4. Shri Yedabeshwarar 
5. Shri Bhaneshwarar 
6. Shri Koneshwarar 
7. Shri Guneshwarar 
8. Shri Bairaveshwarar
9. Shri Agatheeswarar 
10. Shri Vyaseshwarar 
11. Shri Umabageshwarar 
12. Shri Nairutheeshwarar 
13. Shri Brahmeshwarar 
14. Shri Gangeshwarar 
15. Shri Mukthaeswarar 
16. Shri Sathirabaleshwarar