a number of further municipalities were added to the defined areas. Turkey The word metropolitan describes the central municipality governing local services in a province with more than 750.000 residents in Turkey, like Istanbul and its metropolitan municipality, the Istanbul Metropolitan Municipality. There are 30 officially defined "metropolitan municipalities" in Turkey. This classification, however, is only used for administrative purposes, and sometimes contradicts the colloquial use of the term "metro area". As an example, Gebze, a district in Kocaeli province and thus in the juristiction of the Kocaeli Metropolitan Municipality, is arguably within the metro area of Istanbul with many of its residents commuting to Istanbul for work and the Marmaray, a commuter rail line, extending into the district. The district however, as previosuly mentioned, is not a part of Istanbul's provincial limits, and thus not subject to the jurisdiction of its metropolitan municipality. The word metropolitan (municipality) is generally only used as an administrative distinction in Turkey. United Kingdom The United Kingdom government's Office for National Statistics defines "travel to work areas" as areas where "at least 75% of an area's resident workforce work in the area and at least 75% of the people who work in the area also live in the area". The European Union's ESPON group has compiled a separate list of metropolitan areas which covers the UK. See also Notes References External links (page 1 illustrates metropolitan area versus city proper and urban agglomeration) Metropolis.org, An organization of world metropolises Urban Employment Areas in Japan (Metropolitan Employment Areas in Japan) Turismo.fvg.it (Metropolis read by maps in Friuli Venezia Giulia – Northeast of Italy – EU) Geopolis : research group, university of Paris-Diderot, France — Urbanization of the world Cities Capitals Urban geography