Cincinnati Zoo and Botanical Garden is the second-oldest zoo in the United States and is located in Cincinnati, Ohio. The Reptile House is the oldest zoo building in the United States, dating from 1875.It was founded on 65.4 acres (26.5 ha) in the middle of the city, and since then it has acquired some of the surrounding blocks and several reserves in Cincinnati's outer suburbs. The zoo has breeding programs including California Sea Lions, Cheetahs, Sumatran rhinoceros, Malayan tigers, Western Lowland Gorillas, Pottos, and Masai giraffes. Hours: Sun-Sat 9am–5pm