Every district in Kerala has it's own unique culture and characteristics. Kerala also has considerable ethnic diversity. One aspect of the state's rich cultural heritage is manifest in its varieties of religious architecture: ancient Hindu temples with copper-clad roofs, later Islamic mosques with "Malabar gables," and colonial Portuguese Baroque churches. Splendid paintings, especially murals, exhibit distinct local traditions and styles. The land is a flourishing center of the Kathakali dance form. The state has also a rich theatre tradition : the only surviving Sanskrit drama, Kootitiyattamy, is still performed by the Chakkiars of Kerala. Some principles of the Natya Shastra are evident in their presentations.