The park covers 600 acres (2.4 km²), and can be located from miles to the north and from the air because of its large white lion hill figure carved into the side of the Dunstable Downs (part of the Chiltern Hills) below the penguin and old lion enclosures. Due to its size, inside the park, visitors may walk, use the Zoo's bus service, or drive their own cars between the various animal enclosures, or through an 'Asian' area where some animals are allowed to roam free. ZSL Whipsnade Zoo is one of Europe's largest wildlife conservation parks. It is home to 6,405 animals, many of which are endangered in the wild. The majority of the animals are kept within sizeable enclosures; others, such as the peacocks, the South American mara and Australian wallabies, roam freely around the park.