The Archaeological Survey of India (ASI), under the Ministry of Culture, is the premier organization for the archaeological researches and protection of the cultural heritage of the nation. Maintenance of ancient monuments and archaeological sites and remains of national importance is the prime concern of the ASI.
Besides it regulates all archaeological activities in the country as per the provisions of the Ancient Monuments and Archaeological Sites and Remains Act, 1958. It also regulates Antiquities and Art Treasure Act, 1972. For the maintenance of ancient monuments and archaeological sites and remains of national importance the entire country is divided into 24 Circles. Thrissur Circle of Archaeological Survey of India was established in April 1997, separated from Chennai Circle with the Monuments/Sites in Kerala and adjoining districts of Tamilnadu viz. Kanyakumari, Tirunelveli and Nilgiri. There are totally 28 monuments and 9 sites protected under the purview of Ancient Monuments and Archaeological Sites and Remains Act, 1958 and Rules 1959, under the administrative control of the Circle. Most of this monuments and sites were under the protection of erstwhile states of Cochin and Travancore. The monuments protected include Temples, Jaina monuments, a church, Forts and a Palace.
Most of the Temples in Kerala are wooden edifies with granite or laterite plinth. The inner walls of the Mattancherry palace and outer walls of temples are generally covered with valuable mural paintings carried out in traditional Kerala style, while the sites are megalithic in nature.