The Moscow Zoo (Russian: Московский зоопарк) is a 21.5-hectare (53-acre) zoo founded in 1864 by professor-biologists, K.F. Rulje, S.A. Usov and A.P. Bogdanov, from the Moscow State University. In 1919, the zoo was nationalized. In 1922, the ownership was transferred to the city of Moscow and has remained under Moscow's control ever since.
The zoo had an area of 10 hectares (25 acres) when it first opened, with 286 animals. In 1926, the zoo was expanded to adjacent lands, increasing the area to 18 hectares (44 acres). The zoo's original buildings were wooden, built in the old Russian style with intricate wood trims.
In 1990, the zoo was renovated. Notable additions include a new main entrance in the shape of a large rock castle, and a footbridge that connected the old (1864) and new (1926) properties of the zoo. Prior to construction of the footbridge, the zoo operated as two 'separate zoos' because the Bolshaya Gruzinskaya Street divides the properties.
In addition, the zoo was expanded once more. New exhibits were opened including a sea aquarium, an aviary, a creatures of the night exhibit, a sea lion exhibit and a section aimed at children. Waterfalls and streams were added throughout to give the zoo a more natural feeling.
The Moscow zoo has over 6000 animals representing about 1000 species and covers an area of about 21.5 hectares (53 acres) The zoo studies animals behaviour, feeding and reproduction, and breeds rare endangered species.