Rottnest Island

Rottnest Island (Wajuk: Wadjemup), nicknamed "Rotto", is a 19-square-kilometre (7.3 sq mi) island off the coast of Western Australia, 18 kilometres (11 mi) west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, it is an A-class reserve, the highest level of protection afforded to public land.

With Garden Island, Rottnest Island is a remnant of Pleistocene dune ridges. Along with several other islands, Rottnest became separated from the mainland when sea levels rose around 7,000 years ago. The traditional Noongar name for the island is Wadjemup, which means "place across the water where the spirits are". The earliest recorded human presence on Rottnest was at least 17,000 years ago, but visitation and habitation of the island by the Noongar people appears to have ceased following its separation from the mainland.

Rottnest was first documented by Willem de Vlamingh in 1696, who called it 't Eylandt 't Rottenest (lit. 'Rats' Nest Island') after the quokka population. Following establishment of the Swan River Colony (now Perth) in 1829, the island was initially used by British settlers for agriculture, and a permanent settlement was built in Thomson Bay. From 1838 to 1931, Rottnest Island was used as a prison and forced labour camp for over 3,600 Aboriginal people, who were subjected to extremely harsh conditions.

Other past uses of the island include as a military site, and for internment camps housing enemy aliens. Many of the island's buildings date from the colonial period, often made from locally quarried limestone, and are now used as accommodation for holidays.

Rottnest is an unincorporated area with no local government, subject to direct administration by the government of Western Australia. It is administered by the state's Rottnest Island Authority (RIA), which on 1 July 2017 became part of the newly created Department of Biodiversity, Conservation and Attractions. Rottnest is known for its population of quokkas, and is also home to colonies of Australian sea lions and southern fur seals, as well as various birds and three native tree species, notably the Rottnest Island pine.

The island is a popular recreational and tourist destination, with daily ferry services from Perth, the state's capital and largest city. It has a permanent population of around 300 people, with around 780,000 annual visitors.