Devoted to Lord Vishnu, Thrikodithanam Mahavishnu Kshetram alias Adbhuta Narayanan Temple, is one of the five Pancha-Pandava temples in Kerala and among the 108 Vishnu temples in India. This 9th century temple is  located at Thrikodithanam in Changanacherry, 25kms from Kottayam. Adbhuta Narayanan is the chief deity and his idol along with consort Karpagavalli, in standing posture, is made of an unusual black stone called Aanjana-kallu. The temple also houses the idols of Lord Shiva, Lord Krishna, Ganapathi, Narasimha, Nagadevas, and Kshetrapala.

The temple structure is an architectural excellence adorned with beautiful mural paintings. The temple sanctum (sreekovil) is a double-storied structure built on a circular plan. The base of the sanctum is made of three ft high rounded granite stones and centuries old inscriptions can be seen here. The temple complex has two entrance. i.e on the east and west. There is a beautiful and sacred pond near the main entrance, i.e eastern gate. Between the pond and the entrance there a strange granite statue called 'Kazhivetti kallu'.

The annual festival which lasts for 10 days is celebrated during the lunar month of Vrishchigom (November-December). The major highlight of the festival commences after dusk on the 9th day and carries on until the early hours of 10th day morning. It is a huge display of 1001 flares made of cloth bundles dipped in oil which are placed on a pyramidal structure.