The Berlin Zoological Garden (German: Zoologischer Garten Berlin) is the oldest and best known zoo in Germany. Opened in 1844 it covers 34 hectares (84 acres) and is located in Berlin's Tiergarten. With more than 1,500 different species and around 17,500 animals the zoo presents the most comprehensive collection of species in the world.
The zoo and its aquarium had almost 3 million visitors in 2011. It is considered to be the most visited zoo in Europe and one of the most popular worldwide. Regular animal feedings are among its most famous attractions. Globally known animals like Knut, the polar bear, and Bao Bao, the Giant Panda have contributed to the zoo's public image.
The zoo collaborates with many universities, research institutes, and other zoos around the world. It maintains and promotes European breeding programmes, helps safeguard several endangered species, and participates in several species reintroduction programs.