Rottnest Island

Rottnest Island, often colloquially referred to as "Rotto", is a 19-square-kilometre island off the coast of Western Australia, located 18 kilometres west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-class reserve, the highest level of protection afforded to public land.

Together with Garden Island, Rottnest Island is a remnant of Pleistocene dune ridges. Along with several other islands, Rottnest became separated from the mainland around 7,000 years ago, when sea levels rose; the traditional Noongar name for the island is Wadjemup, which means "place across the water where the spirits are". Human artefacts have been found on the island dating back at least 30,000 years, but visitation and habitation of the island by the Noongar people appears to have ceased following its separation from the mainland.

Source: Wikipedia