Brookfield Zoo Chicago, is a zoo located in the Chicago suburb of Brookfield, Illinois. In 1919, Edith Rockefeller McCormick donated land she had received from her father as a wedding gift to the Cook County Forest Preserve District for the development as a zoological garden. The district added 98 acres to that plot and in 1921, the Chicago Zoological Society was established.
It quickly gained international recognition for using moats and ditches instead of cages to separate animals from visitors and from other animals. The zoo was also the first in America to exhibit giant pandas. In 1960, Brookfield Zoo Chicago built the nation's first fully indoor dolphin exhibit, and in the 1980s the zoo introduced Tropic World, the first fully indoor rainforest simulation and the then-largest indoor zoo exhibit in the world