For example, World Heritage Sites might be ancient ruins or historical structures, buildings, cities,[a] deserts, forests, islands, lakes, monuments, mountains or wilderness areas.[4][5] A World Heritage Site may signify a remarkable accomplishment of humankind and serve as evidence of humanity's intellectual history on the planet, or it might be a place of great natural beauty.[7] The sites are intended for practical conservation for posterity, which otherwise would be subject to risk from human or animal trespassing, unmonitored, uncontrolled or unrestricted access, or threat from local administrative negligence.In 1959, the governments of Egypt and Sudan requested the United Nations Educational, Scientific and Cultural Organization (UNESCO) to assist them to protect and rescue the endangered monuments and sites.[15] The project's success led to other safeguarding campaigns, such as saving Venice and its lagoon in Italy, the ruins of Mohenjo-daro in Pakistan, and the Borobodur Temple Compounds in Indonesia.[17] UNESCO reckons the restorations of the following four sites among its success stories: Angkor in Cambodia, the Old City of Dubrovnik in Croatia, the Wieliczka Salt Mine near Kraków in Poland, and the Ngorongoro Conservation Area in Tanzania.[20] A request for a minor boundary change, one that does not have a significant impact on the extent of the property or affect its "outstanding universal value", is also evaluated by the advisory bodies before being sent to the committee.[20] Only three sites have ever been delisted: the Arabian Oryx Sanctuary in Oman, the Dresden Elbe Valley in Germany, and the Liverpool Maritime Mercantile City in the United Kingdom.[citation needed] The Arabian Oryx Sanctuary was directly delisted in 2007, instead of first being put on the danger list, after the Omani government decided to reduce the protected area's size by 90%.The Australian government's actions, involving considerable expense for lobbying and visits for diplomats, were in response to their concern about the negative impact that an "at risk" label could have on tourism revenue at a previously designated UNESCO World Heritage Site.[38][39] In 2021, international scientists recommended UNESCO to put the Great Barrier Reef on the endangered list,[40] as global climate change had caused a further negative state of the corals and water quality.[41] Again, the Australian government campaigned against this, and in July 2021, the World Heritage Committee, made up of diplomatic representatives of 21 countries, ignored UNESCO's assessment, based on studies of scientists, "that the reef was clearly in danger from climate change and so should be placed on the list.""[42] Several listed locations, such as Casco Viejo in Panama and Hội An in Vietnam, have struggled to strike a balance between the economic benefits of catering to greatly increased visitor numbers after the recognition and preserving the original culture and local communities.A major chunk of all world heritage inscriptions are located in regions whose populations generally have lighter skin, including Europe, East Asia, and North America.