What is the world's oldest continuously operating zoo?

Tiergarten Schonbrunn (literally, "Schonbrunn Animal Garden"), or "Vienna Zoo", has been in continuous operation since it opened July 31, 1752, making it the oldest zoo in the world. It is located on the grounds of the famous Schonbrunn Palace in Vienna, Austria and was built on the orders of the then Holy Roman Emperor, Francis I, to serve as an imperial menagerie. Technically, the zoo is even older as a small collection of animals has been kept at the site since 1540. It was not open to the public until 1779 and initially had free admission.

Although the Vienna Zoo has almost shut down a few times, the zoo somehow managed to survive both World Wars and a financial crisis in the 1980s. The zoo has been privatized since 1992 to help sustain its financial situation.

The position of most modern zoos in the world, particularly those with scientific societies, is that they display wild animals primarily for the conservation of endangered species. Some critics and many animal rights activists argue that zoo animals are treated as voyeuristic objects, rather than living creatures, and often suffer due to the transition from being free and wild to captivity. In the last two decades, zoos strongly depend on breeding within zoos, while decreasing the number of wild animals caught.