This cover from Croatia depicts 2 stamps of the same type with a picture of the
Northern Velebit National Park, which is part of the UNESCO site
Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe. This site comprises undisturbed examples of temperate forests that demonstrate the postglacial expansion process of European beech from a few isolated refuge areas in the Alps, Carpathians, Dinarides, Mediterranean, and Pyrenees. The site was originally listed in 2007 as the Primeval Beech Forests of the Carpathians, shared by Slovakia and Ukraine, extended in 2011 to include the Ancient Beech Forests of Germany, and further extended in 2017 and 2021 to include forests in a total of 18 countries.
