(CNN) — A narrow, 10-mile strip of Canadian coastal cliffs dating back more than 500 million years contains the oldest known collection of large fossils in the world.
Located on the southeastern tip of the island of Newfoundland, the Mistaken Point cliffs were added to the exclusive UNESCO World Heritage List on Sunday.
A series of 99 artificial islets built off the the southeast coast of the Micronesian island of Pohnpei sometime between 1200 and 1500 AD were also added to the list.
The ruins on the islets were the ceremonial center of the Saudeleur dynasty, and the structures are evidence of the religious and social practices of the period.
The UNESCO World Heritage Committee inscribed 21 sites on the Wold Heritage List during its annual meeting in Istanbul, Turkey, from July 10 to 17.
The committee cut short its session due to the United Nations security protocol put in place following the coup attempt in Turkey. It will meet in Paris in October to discuss the rest of its agenda.
The United Nations' cultural body meets annually to name natural, cultural and sites of mixed significance around the world to its prestigious preservation list, which now has 1,052 sites considered to be places of "outstanding universal value." The inscribed sites must meet one or more of 10 criteria such as "representing a masterpiece of human creative genius," containing "exceptional natural beauty" or being an outstanding example of a traditional human settlement.
UNESCO has been adding sites to the World Heritage List since 1978.
Nations often spend years developing pitches for inclusion on the list because of its significant cultural cachet and the fame and resources it can attract to sites in need of restoration and protection. They must convince the UNESCO committee that they will protect their sites and support them financially.
Libya's sites added to 'in danger' list
The World Heritage Committee also added several existing sites to the List of World Heritage in Danger because of armed conflict, natural disasters, lack of economic resources and other concerns.
The new Micronesian World Heritage site was also added to the list in danger because of nature's impact on the stone structures.
All five Libyan World Heritage sites were added to the list "because of damage caused by the conflict affecting the country and the threat of further damage it poses," according to a UNESCO press statement.
The five sites are the Archaeological Site of Cyrene, Archaeological Site of Leptis Magna, Archaeological Site of Sabratha, Rock-Art Sites of Tadrart Acacus and the Old Town of Ghadamès.
The World Heritage Committee also added Old Towns of Djenné in Mali due to insecurity in the country and Uzbekistan's Historic Centre of Shakhrisyabz to the list in danger, due to "the over-development of tourist infrastructure in the site."
At the same time, Georgia's Historical Monuments of Mtskheta site was removed from the list in danger in recognition of Georgia's efforts to improve the safeguarding and management of the site, which had been on the list since 2009.
The site includes three Medieval churches, the Holy Cross Monastery of Jvari, Svetitskhoveli Cathedral, Samtavro Monastery and major archaeological remains.
The United States had nominated a collection of Frank Lloyd Wright's structures this year. The committee referred it back to the United States with a request for additional information before it's resubmitted for examination.
After failing to pay its dues for two years, the United States lost UNESCO voting rights in 2013, per the agency's rules.
New World Heritage List sites
Here's this year's full list of newly inscribed sites:
Antigua and Barbuda: Antigua naval dockyard and related archaeological sites
Argentina, Belgium, France, Germany, India, Japan, Switzerland: The architectural work of Le Corbusier, an outstanding contribution to the modern movement
Bosnia and Herzegovina, Croatia, Montenegro, Serbia: Stećci -- medieval tombstones
Brazil: Pampulha Modern Ensemble
Canada: Mistaken Point
Chad: Ennedi Massif natural and cultural landscape
China: Hubei Shennongjia
China: Zuojiang Huashan rock art cultural landscape
Greece: Archaeological site of Philippi
India: Archaeological site of Nalanda Mahavihara (Nalanada University) at Nalanda, Bihar
India: Khangchendzonga National Park
Iran: Lut Desert
Iran: Persian Qanat
Iraq: The Ahwar of southern Iraq: Refuge of biodiversity and the relict landscape of the Mesopotamian cities
Kazakhstan, Kyrgyzstan, Uzbekistan: Western Tien-Shan
Mexico: Archipiélago de Revillagigedo
Micronesia: Nan Madol: Ceremonial Centre of Eastern Micronesia
Spain: Antequera dolmens site
Sudan: Sanganeb Marine National Park and Dungonab Bay -- Mukkawar Island Marine National Park
Turkey: Archaeological site of Ani
United Kingdom: Gorham's Cave complex
UNESCO's new List of World Heritage in Danger sites
Libya: Archaeological site of Cyrene
Libya: Archaeological site of Leptis Magna
Libya: Archaeological site of Sabratha
Libya: Rock-art sites of Tadrart Acacus
Libya: Old Town of Ghadamès
Mali: Old Town of Djenné
Micronesia: Nan Madol: Ceremonial center of Eastern Micronesia
Uzbekistan: Historic center of Shakhrisyabz