The Aktiengesellschaft Cologne Zoological Garden is the zoo of Cologne, Germany. It features over 7,000 animals of more than 700 species on more than 20 hectares. The internationally renowned zoo with an attached aquarium and invertebrate exhibit has an emphasis on primates such as bonobos and lemurs, and is active in preservational breeding of animals that are in danger of becoming extinct. In addition, in-the-wild conservation efforts and research focussing on animals of Madagascar, Wallacea, and Vietnam are actively promoted and supported via cooperation with Cologne University and local projects, such as in the case of Przewalski's Horses.
The zoo was founded in 1860. The world wars led to a phase of stagnation, and the zoo had to close for two years entirely, after virtually being destroyed in World War II. It reopened in 1947; the aquarium was added in 1971. In 1985, the large primate house, one of the main attractions, was opened. Today, the zoo also features a free-flight rainforest hall with free-ranging birds and reptiles opened in 2000, and as the latest addition a large elephant park.