English: The Thiruvanchikulam Mahadeva temple (തിരുവഞ്ചിക്കുളം ശിവക്ഷേത്രം), also called the Kilatali Siva temple of Thiruvanchikalam, is a c. 11th century Hindu temple built by the Chera dynasty near their capital. The regional tradition attributes it to Rajasekhara, the successor of Kulasekharavarman. The site is likely older because it is mentioned in the Tamil classic Tevaram (the only Kerala site).

The Thiruvanchikulam temple site is large. It has many structures that were added and restored between the 12th and 20th century, as evidenced by several Malayalam inscriptions from the 19th century. The oldest shrine of the temple was built from laterite, has a square floor plan, a mukhamandapa and a namaskara mandapa. The vimana has two storeys (dvi-tala), while the wall is divided into bhadras and karas. It includes other Hindu architectural elements such as panjaras and kudyastambhas. Though dedicated to Shiva, the complex includes shrines for all major historic Hindu gods and goddesses.

The temple is notable for its 16th and 17th century murals which are a part of national heritage protected by the ASI. These include the Nataraja, Rama avatara of Vishnu, and Devi panjakshari.