Smithsonian's National Zoo and Conservation Biology Institute is one of the most celebrated zoological institutions in the world, spanning 163 acres within Washington, D.C.'s Rock Creek Park and home to more than 2,100 animals representing nearly 400 species. Admission is free, reflecting the zoo's role as part of the Smithsonian Institution, and highlights include giant pandas Bao Li and Qing Bao, making it the only place in the United States offering free giant panda viewing. Major exhibits encompass Elephant Trails, the Great Ape House, Cheetah Conservation Station, American Trail, and the Reptile Discovery Center featuring some 70 species of reptiles and amphibians. The zoo's conservation mission extends to the Smithsonian Conservation Biology Institute, which breeds rare species and trains wildlife professionals globally, with about 25 percent of the zoo's species classified as endangered. The National Zoo has been a cornerstone of wildlife conservation and public education since its founding in 1889.
