[3] Frederick Law Olmsted, the original landscape designer of Franklin Park, created plans for a future zoological garden.

However, Shurtleff's design for the zoo was modest and was intended to be in harmony with key elements of the plan, such as a half-mile long grassy mall called "the Greeting", which began at Peabody Circle.

Soon afterward, the zoo received its first professionally trained zoologist to serve as its director, Walter D. Stone.

In 1970, the Boston Zoological Society assumed some, but not all, management of the zoo, while the state continued to provide funding for the facility.

In 1973, a new $24 million master plan, which would "recommend replacing 'the Greeting' with new zoo exhibits", was formulated to revitalize and expand the facility, and included several new domed pavilions, stressing an African theme.

After eleven years of construction at a cost of $26 million, the new African Tropical Forest Pavilion opened on September 9, 1989.

This private, non-profit corporation also took over management of the Stone Zoo, which would reopen in June 1992 after being closed for 18 months due to state budget cuts.

The building mimics the animals' natural environment with streams, moats, faux-rock structures, hidden fences and barriers.

The exhibit includes western lowland gorillas, fruit bats, dwarf crocodiles, ocelots, ring-tailed lemurs, West African pottos, Baird's tapirs, Linne's two-toed sloths, green anacondas, giant anteaters, Ruppell's griffon vultures, De Brazza's monkeys, cotton-top tamarins, pygmy hippos and various birds and reptiles.

This exhibit was included in the zoo's 1973 master plan, and was originally home exclusively to African rainforest animals; however, more Central and South American species began being displayed in the Tropical Forest by the late 1990s.

[9] In spring 2020, a wildlife trade exhibit showcasing artifacts will be displayed in the tropical forest public areas.

Other animals included are lowland nyalas, red river hogs, kori bustards and African spurred tortoises.

Outside, there is a large flight cage for Andean condors, Eurasian griffon vultures, and Steller's sea eagles, and other birds from around the world including black crakes, boat-billed herons, Gouldian finches, great hornbills, green aracaris, Indian peafowl, kea, lesser flamingos, sunbitterns, violet turacos and various waterfowl.

Children's Zoo: A three-acre complex which includes a new, walk-through aviary with assorted Asian birds, black-tailed prairie dogs, red pandas, turtles, Baikal teals, and Reeve's muntjacs.

The animals include Poitou donkeys, Morgan horses, Guinea hogs, Nigerian dwarf goats, Black Welsh Mountain sheep, heritage breeds of chickens and barn owls.