Founded in 1927, the 64-acre (26 ha) Rio Grande Zoo, located in Albuquerque, New Mexico, is a facility of the Albuquerque Biological Park. Some of the most popular of the over 200 species are seals and sea lions, chimpanzees, gorillas, orangutans, elephants, polar bears, giraffes, hippos, camels, tamarins, koalas, Mexican wolves, mountain lions, monkeys, jaguars, zebras, and rhinos. Sections of the zoo include an Africa exhibit area, an Australia exhibit area, the "Cat Walk", and Tropical America. A narrow-gauge railroad connects the zoo to the other facilities of the Albuquerque Biological Park. Walking distance through the zoo is 2.27 miles (3.65 km).