The San Diego Zoo in Balboa Park, San Diego, California, is one of the largest and most progressive zoos in the world, with over 4,000 animals of more than 800 species. It is also one of the few zoos in the world that houses the giant panda.[1] It is privately operated by the nonprofit Zoological Society of San Diego. How Big Is The San Diego Zoo? 107 acres (0.43 km2) of parkland leased from the City of San Diego, and ownership of all animals, equipment and other assets rests with the City of San Diego.