Ayutthaya Historical Park
In 1991, part of Ayutthaya Historical Park was declared a UNESCO World Heritage Site under criteria III as an excellent witness to the period of development of a true national Thai art. The inscribed area covered only 289 ha of the central and southwestern parts of Ayutthaya Island; as a result, only certain groups of historical sites are under UNESCO protection. The sites including Wat Ratchaburana, Wat Mahathat, Wat Phra Sri Sanphet, Wat Phra Ram, and Wiharn Phra Mongkhon Bopit. The sites that are not part of World Heritage sites are the sites beyond Ayutthaya Island, for example, Wat Yai Chai Mongkon, Wat Phanan Choeng, Wat Chaiwatthanaram, and Wat Phu Khao Thong.