The Flemish Diamond (in Dutch: Vlaamse Ruit) is the Flemish reference to a network of four metropolitan areas in Belgium, three of which are in the central provinces of Flanders, together with the Brussels Capital Region. It consists of four agglomerations which form the four corners of a diamond shape: Brussels, Ghent, Antwerp and Leuven. Over five million people live in this area, with a population density of more than 800 per square kilometre.<ref

name=terminology>Note: There appear no generally accepted precise definitions with clear similarities or distinctions for, e.g.: 'conurbation', 'megaplex', metropolitan region, metropolitan area, urban agglomeration. For related details, see e.g.: