Zoo exhibits where visitors enter enclosures of non-aggressive species, such as lemurs, marmosets, birds, lizards, and turtles. Visitors are asked to keep to paths and avoid showing or eating foods that the animals might snatch. Some zoos keep animals in larger, outdoor enclosures, confining them with moats and fences, rather than in cages. Safari parks, also known as zoo parks and lion farms, allow visitors to drive through them and come in close proximity to the animals. Sometimes, visitors are able to feed animals through the car windows. The first safari park was Whipsnade Park in Bedfordshire, England, opened by the
Milwaukee County Zoo mall, and grizzly bear den. The zoo also opened with a gauge miniature railway, the "Zoo Line", which carried visitors around the zoo to view the exhibits and construction. The Zoo Line (now known as the "Safari Train") has continued to run, operating with real steam locomotives. In 1959, construction started on the dall sheep mountain and the Alaskan bear exhibit. On May 13, 1961, the Milwaukee County Zoo officially opened to the public. Later additions included the aviary (1962), the Australian building (1963), the original animal hospital (1963), the small mammal building (1965), the aquarium (1968), and the reptile