Greetings from the United Nations, Vienna

As you know, the United Nations is the only organization in the world which is neither a country nor a territory that is permitted to issue postage stamps. It is also the only postal authority to issue stamps in three different currencies, namely U.S. dollars, Swiss francs and Euro. These stamps are issued simultaneously at UN offices in New York, Geneva and Vienna and valid for postage on mails only from the corresponding office. I am lucky again to receive a postcard sent from UN office in Vienna, after the previous one from New York. Many thanks to my friend Betti who lives in Vienna and sent me this wonderful surprise when she visited the UN office! The two stamps on the left with lower face value were issued to feature two UNESCO World Heritage Sites in Austria: the Eggenberg Castle in old city of Graz (0.04 Euro) and the Semmering Railway (0.07 Euro), very beautiful and much appreciated! 

Reference:  UNPA