Built in 1425 A.D by the Raja of Palakkad Kombi Achan, Kalpathy Viswanathaswamy temple is the oldest Shiva Temple in Malabar. The temple also known as Kasiyil Pakuthi Kalpathy, situated on the bank of river Neela Bhagirathi resembles the Banaras temple on the banks of the Ganges. The temple is around 3 kms from Palakkad. Apart from the main deity of Viswanadhaswamy, there are several other deities consecrated in the temple which includes Subrahmanyaswamy, Nataraja, Vinayaka, Dakshinayana Murthy, Nandeeswaran etc. 

The temple rituals are performed by the Tamil Brahmins which were earlier conducted by Kerala Brahmins. The annual chariot festival known as Kalpathy Ratholsavam is associated with this temple.