Each nominated site is independently evaluated by two Advisory Bodies –IUCN for natural properties and ICOMOS for cultural properties. IUCN and ICOMOS work together for the evaluation of mixed (natural and cultural) properties, while IUCN also provides input, where relevant, to the ICOMOS evaluation of cultural landscapes.
Each year IUCN, as technical advisory body to the World Heritage Committee, receives all complete World Heritage nominations for natural and mixed properties and cultural landscapes from the UNESCO World Heritage Centre.
Between May and April, IUCN carries out a rigorous, year-long evaluation process before providing its recommendations to the UNESCO intergovernmental World Heritage Committee. The Committee, meeting annually in June or July, decides which sites to inscribe on the World Heritage List. It can also defer its decision, refer a nomination back to the State Party for further work or reject inscription.
The IUCN evaluation process includes a field mission to each nominated site to meet the authorities and stakeholders, and to assess the management and integrity of the site. IUCN also seeks input from international experts knowledgeable about the sites or the natural values they represent. These reviewers carry out desk reviews of each nomination and provide views on their global significance, management and integrity.
IUCN annually seeks input from international experts in the evaluation of World Heritage nominations. Experts are asked to contribute voluntarily by carrying out a desk review of one or more nominations. This input is critical to the IUCN Evaluation Process and in ensuring the ongoing credibility of the World Heritage List.
