A United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site is a place (such as a forest, mountain, lake, island, desert, monument, building, complex, or city) that is listed by the UNESCO as of special cultural or physical significance. The list is maintained by the international World Heritage Programme administered by the UNESCO World Heritage Committee, composed of 21 states parties which are elected by their General Assembly.
The programme catalogues, names, and conserves sites of outstanding cultural or natural importance to the common heritage of humanity. Under certain conditions, listed sites can obtain funds from the World Heritage Fund. The programme was founded with the Convention Concerning the Protection of World Cultural and Natural Heritage, which was adopted by the General Conference of UNESCO on 16 November 1972. Since then, 190 states parties have ratified the Convention, making it one of the most adhered to international instruments. Only the Bahamas, Liechtenstein, Nauru, Somalia, South Sudan, Timor-Leste and Tuvalu are not Party to the Convention.
As of June 24, 2011 in Saint Petersburg, 962 sites are listed: 745 cultural, 188 natural, and 29 mixed properties, in 157 states. By sites ranked by country, Italy is home to the greatest number of World Heritage Sites with 48 sites, followed by Spain (44) and China (43). UNESCO references each World Heritage Site with an identification number; but new inscriptions often include previous sites now listed as part of larger descriptions. As a result, the identification numbers exceed 1200 even though there are fewer on the list.
Angkor (Khmer: អង្គរ, "Holy City") is a region of Cambodia that served as the seat of the Khmer Empire, which flourished from approximately the 9th to 15th centuries. The word Angkor is derived from the Sanskritnagara (नगर), meaning "city". The Angkorian period began in AD 802, when the KhmerHindu monarch Jayavarman II declared himself a "universal monarch" and "god-king", until 1351, when Angkor first fell under Ayutthayan suzerainty, to 1431, when Ayutthaya put down a rebellion and sacked the Khmer capital, causing its population to migrate south to Longvek.
The ruins of Angkor are located amid forests and farmland to the north of the Great Lake (Tonlé Sap) and south of the Kulen Hills, near modern-day Siem Reap city (13°24′N, 103°51′E), in Siem Reap Province. The temples of the Angkor area number over one thousand, ranging in scale from nondescript piles of brick rubble scattered through rice fields to the magnificent Angkor Wat, said to be the world's largest single religious monument. Many of the temples at Angkor have been restored, and together, they comprise the most significant site of Khmer architecture. Visitor numbers approach two million annually, and the entire expanse, including Angkor Wat and Angkor Thom is collectively protected as a UNESCOWorld Heritage Site. This popularity of the site among tourists presents multiple challenges to the preservation of the ruins.