English: The Thirunillai temples in the suburbs of Palghat town are restored ruins of a major 11th to 12th century Shiva and Vishnu temples complex. The Shiva temple has a circular floor plan while the Vishnu temple has a square floor plan.

The nalambalam of the complex was made from laterite blocks, while the upapithas of the temples was made from granite. The sandhara-style Shiva shrine faces east, has a circular enclosed circumambulation passage and a square sanctum inside. It has a stone-built ceiling with stepped arches and a dome shape. By corbelling, the stone ceiling has three tiers. The sanctum slabs form a square and then an octagon inside. A lotus-medallion-carved block fills the center. Such an architecture and construction method is not found in Tamil Nadu temples, but is found in the Chalukyan temples in Karnataka and Maharashtra. This temple therefore is notable evidence of ideas being shared between Deccan kingdoms and Kerala.

The phalaka of the temple has a Vatteluttu inscription mentioning Chera king, and this is from early 12th century.