The International Council on Monuments and Sites (ICOMOS) is an international non-governmental organization of professionals, dedicated to the conservation of the world's historic monuments and sites founded in 1965.
ICOMOS works for the conservation and protection of cultural heritage places. It is the only global organisation of this kind, which is dedicated to promoting the application of theory, methodology, and scientific techniques of conservation of the architectural and archaeological heritage. Its work is based on the principles enshrined in the 1964 International Charter on the Conservation and Restoration of Monuments and Sites – the Venice Charter.

ICOMOS is a network of interdisciplinary experts – architects, historians, archaeologists, art historians, geographers, anthropologists, engineers and town planners. As a scientific consultant of UNESCO, ICOMOS provides the World Heritage Committee with evaluations of properties with cultural values proposed for inscription on the World Heritage List, as well as with comparative studies, technical assistance and reports on the state of conservation of inscribed properties.

ICOMOS administrative organization arranges the establishment of National Committees organised in countries member states of UNESCO and Specialised Scientific International Committees on various cultural heritage themes and issues.
The Scientific committees are ICOMOS technical bodies. As such, they undertake research, develop conservation theory, guidelines, and charters, and foster training for better heritage conservation, promote international exchange of scientific information and carry out common projects.

Information source: ICOMOS official website