The moolavar is Devarajan also called Sri Hari and the Thayar Sri Harilakshmi. The Theertham is Chakra Theertham and the Vimanam Sri Hari Vimanam.
As per the sthala purana Vishnu is considered to be the Aranya swaroopi - the forest of Naimisaranyam. The entire forest is believed to have been the abode of 60000 sages. The varaha purana says that Lord Vishnu threw His chakra and the entire army of Danavas, the demon king was destroyed at this place in one "nimisha", hence the name Naimisharanya. Rama is supposed to have taken bath in the Hatyaharaana Theertham here, to purify himself of the sin of having killed Ravana. The main temple here is of Lalitha Devi, and there is a large congregation of pilgrims on New moon days.
