The linga behind the original linga at the temple was consecrated by Agastya muni. The lingam is on the second floor of the temple.
There is a place to sit and meditate. You can go into meditative states here effortlessly.
This Temple is also the mukti place of Amaraneedi Nayanar.
How to get there:
The temple is located 12 kms East of Kumbakonam.
Map: https://goo.gl/maps/KXz58r68TFnS4Zbt8
About Agastya Linga
According to the Hindu legend, the god Shiva sent the sage Agastya to this place to balance the weight of the deities attending his marriage with Parvati. At the spot where the temple now stands, Agastya witnessed the marriage of Shiva and Parvati. The sage installed a lingam (symbol of Shiva) behind the main lingam to worship Shiva.
Source:
https://en.wikipedia.org/wiki/Kalyanasundaresar_Temple,_Nallur
