Also located on the grounds of Schonbrunn Palace, the Vienna Zoo can be visited as well. It is the oldest continuously operating zoo in the world and focuses on preserving endangered species. The most popular attraction in the zoo is the giant pandas. The Vienna Zoo dates back to 1752 when Emperor Franz Stephan I built it to house his menagerie of exotic animals. Today the zoo focuses more on species preservation and housing animals as close to their natural environment as possible. Many of the original buildings of the Vienna Zoo are still intact.