-they are key centres for financial institutions, such as banking, insurance, specialized investment organizations, and stock exchanges.
-they contain the headquarters of large corporations, many of which are transnational companies.
-they are typically home to national and/or subnational governments and/or supranational organizations such as the United Nations, the European Union, and the World Bank.
-culturally, they are commonly heterogeneous, serving as home to diverse ethnic identities, linguistic groups, and cultural traditions.
-they are transportation and communications centre, with efficient intra-urban movement and various interregional and international links.