Henry Doorly Zoo - a fun family destination - is located just south of Nebraska I-80 and exit 454 in Omaha, Nebraska. The history of the Henry Doorly Zoo evolves from the small Riverview Park zoo, which was established in 1894. With the growing number of animals and exhibits, the zoo’s facilities were improved during the first half of 20th century. In 1952, the Omaha Zoological Society was organized to improve the zoo and to provide administrative help to the city. In 1963, Margaret Hitchcock Doorly – wife of Henry Doorly – donated $750,000 to the zoo with the stipulation that the Zoo be named after her late husband. In 1965, the society was reorganized to plan reconstruction of the zoo for the city as a non-profit organization. Thus, the first phase of the zoo, which constituted bear grottos, gorilla and orangutan buildings, and Ak-Sar-Ben Nature Kingdom, were completed and dedicated to Henry Doorly. During 1967 and 1968, a pachyderm exhibit was built on the old baseball diamond site, and the Omaha Zoo Railroad was inaugurated. Many additions were made in later years, which include the opening of a hospital and nursery complex in 1979, and the world's second largest walk-through aviary, in 1983. The zoo spans an area of about 130 woodland acres, and includes 15 major animal habitats. It manages more than 17,000 specimens representing about 1,000 species that includes mammals, birds, reptiles, amphibians, fish, and invertebrates. It also exhibits 44 species that are listed as endangered by Convention on International Trade in Endangered Animals (CITE) as well as seven threatened species. Henry Doorly Zoo has many innovative facilities and exhibits that preserve a broad array of species and vividly present them to the public. Mutual of Omaha's Wild Kingdom Pavilion, the Lozier IMAX Theater, and the Cat Complex showcase fascinating wildlife and exotic places. Other innovations include the Scott Aquarium, which has the longest zigzaging underwater tunnel in the world; Lied Jungle, the world's largest indoor rainforest; the Desert Dome, the world's largest indoor desert; Kingdoms of the Night; Hubbard Gorilla Valley; and the Hubbard Orangutan Forest, provide immersive environments that display animals in their natural habitats. In addition, Henry Doorly Zoo arranges wildlife safaris through the Lee G. Simmons Conservation Park and Wildlife Safari - displaying Nebraska's wildlife as it once lived. Henry Doorly Zoo is also a leader in animal conservation and research. The Bill and Berniece Grewcock Center for Conservation and Research provides state of the art medical and research capabilities in the animal care and management, reproductive physiology, nutrition, genetics and genome resource banking fields. In addition, the zoo also has an aggressive undergraduate, graduate, and post-graduate student program, providing valuable educational experience to North American and overseas students. Gift shops are located at the north and south entrances of the zoo and in the aquarium.