Peppermint Grove is an affluent western suburb of Perth, Western Australia on the north bank of the Swan River at Freshwater Bay. It has been rated as Australia's most expensive suburb. Its local government area, the smallest in the country, is the Shire of Peppermint Grove. The suburb was named after its trademark "Peppermint trees" (Agonis flexuosa) lining many streets. The suburb has long been associated with Western Australia's wealthiest and oldest families: see Robert Pascoe's "Peppermint Grove: Western Australia's Capital Suburb". Their prosperity is reflected in historic houses in the area, such as 'St Just' and The Cliffe. Peppermint Grove remains, to this day, the suburb with the highest average weekly income in Western Australia. Its Sydney and Melbourne equivalents, as Pascoe points out, would be Vaucluse and Toorak. Colin Barnett, Premier of Western Australia, has dubbed the suburb "Australia's Monaco" due to its small size and concentration of wealth.