27 places to visit before it's too late

Representatives of UNESCO regularly hold meetings in which they decide which sites will be added to the list of sites under threat.

According to UNESCO, 55 sites are currently under threat. Here are some of the most notable ones to visit before they disappear from the face of the earth.

Great Barrier Reef, Belize. Threatened since 2009. This system is a habitat for some endangered marine species. Problems arise from overexploitation of marine resources, coastal development, tourism, industrial development and oil and gas exploration.

Everglades National Park, USA. Threatened since 2010. This place has been called "a green river flowing from the interior to the sea." The exceptional diversity of aquatic habitats has made it home to a large number of birds, reptiles and endangered species. But the park is in danger due to the shrinking of its aquatic ecosystem.

Bagrati Cathedral and Gelati Monastery in Kutaisi, Georgia. Under threat since 2010. The cathedral is a fine example of Georgian medieval architecture. But there is a serious problem associated with the ongoing reconstruction, which, according to UNESCO, will undermine the integrity and authenticity of this work of architectural art.

Chan Chan, Peru. Threatened since 1986.

Comoe National Park, Ivory Coast. Endangered since 2003. The park was listed as a World Heritage in Danger in 2003 due to the potential impact of civil unrest, declining large mammal populations due to uncontrolled poaching, and the lack of an effective management mechanism.

Abandoned ghost town of Humberstone, Chile. Threatened since 2005. Looting, destruction and lack of maintenance have threatened the existence of this place.

The complex of buildings of the Liverpool port, UK. Under threat since 2012. The Port of Liverpool building complex has been placed on the World Heritage in Danger List due to a proposed massive repurposing of the historic wharfs north of the city centre.

Tropical forests of the province of Atzinanana, Madagascar. Threatened since 2007. These relic forests are critical to maintaining the ongoing ecological processes necessary for the survival of Madagascar's unique biodiversity. Key management issues are the effective control of agricultural encroachment and the use of forest resources for logging, hunting and gem mining.

Basilica of the Nativity and Pilgrims' Trails, Bethlehem, Palestine. Threatened since 2012. The roof structure of the main church is very vulnerable due to lack of maintenance and repair. And the dramatic increase in the number of vehicles and the development of industry in the historic city have caused environmental pollution, which negatively affects the facades of both the Church of the Nativity and buildings along the pilgrimage route.

Medieval monuments, Kosovo. Threatened since 2004. Kosovo's Orthodox monasteries have been threatened with extinction, in large part due to prolonged fighting in the region.

Hang in there, Bolivia. Threatened since 2014. The city is in danger due to ongoing uncontrolled work in the mountains of Cerro Rico.

Nan Madol, Micronesia. Under threat since 2016.

Selous Game Reserve, Tanzania. Under threat since 2014.

Simen National Park, Ethiopia. Under threat since 1996.

Niokolo-Koba National Park, Senegal. Under threat since 2007.

Port of Coro, Venezuela. Under threat since 2005.[adsp-pro-21]This is one of the first colonial cities in Venezuela (founded in 1527). It has about 602 historic buildings. The port of Koro is in a vulnerable position due to inappropriate development within it and lack of city control.

Rainforests of Sumatra, Indonesia. Under threat since 2011.

Virunga National Park, Congo. Under threat since 1994.

Old City, Jerusalem, Israel. Under threat since 1982.

Shakhrisabz, Uzbekistan. Under threat since 2016.[adsp-pro-16]This listed building has been placed on the World Heritage in Danger List due to over-development of tourism infrastructure at the site.

Ancient complex of Abu Mena, Egypt. Under threat since 2001.

The ancient city of Hatra, or El-Khadr, Iraq. Under threat since 2015.

Jam minaret, Afghanistan. Under threat since 2002.

Old part of Sana'a, Yemen. Under threat since 2015. In a separate group, UNESCO included historical and architectural sites, where most tourists are unlikely to want to go. The reason for this is the unstable situation in the countries where art monuments are located.

The castles of Krak des Chevaliers and Qal'at Salah ad Din, Syria. Under threat since 2013.

Timbuktu, Mali. Under threat since 2012.

The ancient city of Leptis Magna, Libya. Under threat since 2016.