The UNESCO (United Nations Educational Scientific and Cultural Organization) with headquarters in Paris was founded in London in 1945 as a specialized agency of the UN (almost 200 states). It awards the title of World Heritage (World Cultural Heritage and World Natural Heritage) to sites which are of world importance because of their uniqueness, authenticity and integrity and which are proposed by the states in which they are located. The title is based on the World Heritage Convention ratified by 190 states. As of 2019, the UNESCO World Heritage List comprised 1,121 monuments in 167 countries. Of these, 869 are listed as cultural monuments and 213 as natural monuments, while a further 39 monuments are listed as mixed cultural and natural heritage sites. 39 World Heritage sites are classified as cross-border or transnational, i.e. they are assigned to two or more states.