The San Diego Zoo is a zoo in San Diego, California, located in Balboa Park. It began with a collection of animals left over from the 1915 Panama–California Exposition that were brought together by its founder, Dr. Harry M. Wegeforth. The zoo was a pioneer in the concept of open-air, cage-less exhibits that recreate natural animal habitats. The zoo sits on 100 acres of land leased from the City of San Diego. It houses over 12,000 animals of more than 680 species and subspecies.