The main Sanctum Sanctorum of Anandavalleeswaram Sri Mahadevar temple is 1200 years old and it constructed in Teak wood.

It believe that both the deities are said to be in a happy state and hence the temple name Anandavalleeswaram (Anandam in Malayalam means 'Joy').

Initially the temple had only Shiva as the deity and Devi Parvati was consecrated later in the form of Anandavally.

Even though Devi Parvati's garbagriha is the immediate one to the entrance, one is supposed to enter the temple only through the door which lead to the sanctum sanctorum of Lord Shiva.

The shrine dedicated to Maha Vishnu with his two consorts and Sree Krishnan is very peculiar, since it is the only temple in the whole world with such a system.