To be included on the World Heritage List, sites must be of outstanding universal value and meet at least one out of ten selection criteria. These criteria are explained in the Operational Guidelines for the Implementation of the World Heritage Convention which, besides the text of the Convention, is the main working tool on World Heritage. The criteria are regularly revised by the Committee to reflect the evolution of the World Heritage concept itself.
Until the end of 2004, World Heritage sites were selected on the basis of six cultural and four natural criteria. With the adoption of the revised Operational Guidelines for the Implementation of the World Heritage Convention, only one set of ten criteria exists.
* To bear a unique or at least exceptional testimony to a cultural tradition or to a civilization which is living or which has disappeared;
* To be an outstanding example of a type of building, architectural or technological ensemble or landscape which illustrates (a) significant stage (s) in human history;
* To be an outstanding example of a traditional human settlement, land-use, or sea-use which is representative of a culture (or cultures), or human interaction with the environment especially when it has become vulnerable under the impact of irreversible change.
Properties inscribed on the World Heritage List
The historic churches of Mtskheta, former capital of the Kingdom of Georgia, are typical of medieval religious architecture in the Caucasus region; they were inscribed on the World Heritage List in 1994.
Georgian culture gives pride of place to popular song as typified by the Chakrulo, a polyphonic song using metaphors and complex musical ornamentation, whose medieval origin is linked to the cult of wine and winemaking. In 2001 UNESCO proclaimed Georgian Traditional Polyphony a Masterpiece of the Oral and Intangible Cultural Heritage.