Annamalai Temple is also another religious shrine of Idukki. It is around 1800-year old temple. Main deity of this temple is Lord Shiva. The idol of Lord Shiva is made of made of stone and metal. Main Attraction of this temple is window with 9 lattices that representing Navagrahas (nine planets), and another widow with 5 lattices representing Pancha Bhoothas (5 devil elements). There is a stepwell in Annamalai Temple that holds water always. The water in it is considered sacred and it never dries even in extreme drought. Annamalai Temple was managed by a private trust is but now under the control of Archaeological Survey of India for its historic importance. In the Thrissur and Calicut museums, the main relics of this temple are kept. Annamalai Temple was built in the traditional Chola style architecture. It is made of stone.