Rottnest Island (known as Wadjemup to the local Noongar people, and otherwise colloquially known as Rotto) is an island off the coast of Western Australia, located 18 kilometres (11 mi) west of Fremantle. The island covers 19 square kilometres (7.3 sq mi) and is administered by the Rottnest Island Authority under a separate act of parliament. Rottnest is a popular holiday destination, and there are daily ferry services to Perth, the state's capital and largest city. It has a permanent population of around 100 people, with around 500,000 annual visitors (and up to 15,000 visitors during periods).