Leningrad Zoo is located in Alexander Park - of which it is effectively part - on the Petrograd Side. It was founded by two animal-lovers - Sofia and Julius Gerhardt - in 1865. Today it is the second largest Zoo in Russia (after Moscow Zoo), with 2,000 animals from 410 species.

In 1873 the Zoological Garden was taken over by Ernest Rost, who replenished its collection of animals, carried out repairs on all of its buildings and equipment, and made it into a profitable business by splitting it into two parts - zoological and commercial. The Zoo was used for circus performances and concerts by choirs and orchestras, and was also home to restaurants. The Zoo's increased profitability meant it could afford to expand its collection of animals - it gained giraffes, orang-utans, anteaters and African elephants - and create more pleasant living conditions and new enclosures for them. Rost left in 1897, and Zoo began to decline. In 1909 it was closed to visitors.