Schönbrunn Zoo is a 17-hectare zoo in the city of Vienna, Austria. Established in 1752, it is the world's oldest zoo still in operation. It is also a UNESCO World Heritage Site, being a part of the Schönbrunn Palace gardens. It generally receives more than 2 million visitors every year. As of 2021, it presented a total of 707 different species with around 8,250 specimens. Its primary attractions include the giant pandas, being one of only 27 zoos in the world to house them.