Abstract: This work is the first part of the article, the subject of which is the practice of fulfillment by Benin, Niger and Burkina Faso of international obligations to protect the transboundary object of the world natural heritage of the "W-Arly-Panjari" Complex, as well as the practice of managing activities for the protection of such an object as Wadden Sea, located in the territories of Germany, Denmark and the Netherlands. The authors highlight the general problems of protecting world heritage sites in the framework of the implementation of the provisions of the Convention, as well as review and analyze the main activities for coordinating the actions of national authorities to preserve and maintain unique natural complexes, in particular, in terms of the implementation of management plans. The analysis of the experience of cooperation between the authorities of Benin, Niger and Burkina Faso with the authorities of the world heritage protection system in relation to the W-Arly-Panjari Complex, as well as Germany, Denmark and the Netherlands in relation to the Wadden Sea, leads to the conclusion that the interaction of national and international funds is effective protection of nature and the need to develop measures aimed at strengthening cooperation between states, including within the framework of the functioning of supranational systems and legal institutions in order to preserve transboundary natural heritage sites.