The Australian Botanic Garden Mount Annan is a 416-hectare botanical garden located in a hilly area of the south-western Sydney suburb of Mount Annan, between Campbelltown and Camden, New South Wales. It is the largest botanical garden in Australia, specializing in native plants, with a collection of over 4000 species. Officially opened in 1988, it was known as Mount Annan Botanic Garden, until 2011.