Cracow 1991 83 26. Acknowledging the important contribution of religious faiths, institutions and organizations to the cultural heritage, the participating States will co-operate closely with them regarding the preservation of the cultural heritage and pay due attention to monuments and objects of religious origin whose original communities no longer use them or no longer exist in the particular region. 27. Bearing in mind the important role that regional aspects of culture may play in linking people across national borders, the participating States will favour regional co-operation at the level of local and national authorities as well as non-governmental organizations with a view to fostering good-neighbourly relations. 28. The participating States will accord due attention to strengthening the heritage of popular culture of the past, including indigenous and vernacular cultures, and to encouraging a contemporary popular culture within the framework of their overall efforts for the preservation, study, protection and promotion of mutual awareness of their cultural heritage. The participating States note the importance of research into various forms of expression of past and present cultures — symbolic practices, technical objects and knowledge, folk art, languages — and the importance of doing what is necessary to highlight them. 29. The participating States will also pay attention to more recent contributions to the cultural heritage (art, including architectural works, of the 20th century). 30. The participating States will co-operate in preventing the illegal circulation of cultural objects, for example by considering adhering to the relevant international instruments. 31. The participating States will strive to preserve and protect those monuments and sites of remembrance, including most notably extermination camps, and the related archives, which are themselves testimonials to tragic experiences in their common past. Such steps need to be taken in order that those experiences may be remembered, may help to teach present and future generations of these events, and thus ensure that they are never repeated. 32. The interpretation of sensitive sites of remembrance can serve as a valuable means of promoting tolerance and understanding among people and will take into account social and cultural diversity. 33. The participating States recognize that, in defining priorities for preservation, it is important to take into account both the intrinsic value of the cultural heritage, its relative state of deterioration and its historic cultural content. To this effect they will, as appropriate, endeavour to promote the use of risk charts, the exchange of information and the organization of onsite workshops, ideal also for the involvement of younger generations. 34. The participating States bear in mind that the preservation of the status of monuments and sites related to their history and culture, wherever they are located, constitutes an integral part of the overall efforts within the CSCE for the preservation and protection of the common cultural heritage.