This cover from United Nations (Vienna Office) depicts 4 stamps of the same type, celebrating the World Heritage Site
Olympic National Park, USA. This National Park is located in the State of Washington, on the Olympic Peninsula. The park has four regions: the Pacific coastline, alpine areas, the west-side temperate rainforest, and the forests of the drier east side. In 1976, Olympic National Park was designated by UNESCO as an International Biosphere Reserve, and in 1981 as a World Heritage Site.
