When did the world's oldest zoo open?

Schönbrunn Zoo was established in 1752 by Holy Roman Emperor Francis I, husband of Empress Maria Theresa, in the grounds of Schönbrunn Palace. It began as a private royal menagerie and was opened to the public in 1779. The original baroque pavilion at its centre still stands. Earlier animal collections existed in ancient Egypt, China and elsewhere, but Schönbrunn is recognised as the oldest zoo that has operated continuously to the present day. Schönbrunn Palace, including the zoo, is part of a UNESCO World Heritage Site.