Find here under the temple sites of the Historic City of Ayutthaya, a UNESCO World Heritage Center (WHC 576) since 13 December 1991. The boundaries of the World Heritage Historical Park were submitted by the Thai authorities to UNESCO on 11 October 1991. Only 95 sites on the city island fall under the World Heritage Center. 67 sites of these 95 sites are temple ruins, which are listed hereunder. From these 67 temple sites, 22 sites have no traces of brickwork anymore as encroachment within Ayutthaya's WHC kept ongoing since the nineties 6 other sites or simply brick mounds, some hardly excavated. Within these WHC boundaries, numerous other temple ruins - mapped in the mid-19th and early 20th century centuries - vanished mainly due to the area's urbanisation. A list of these by-gone monasteries can also be found on this webpage. [References: Note 826/1530 Fine Arts Department - transmitted 17 August 1987. Historic City of Ayutthaya 2533 / page 19.]