Megacity

Urban area with a total population in excess of ten million people

A megacity is a very large city, typically with a population of more than 10 million people. The United Nations Department of Economic and Social Affairs (UN DESA) in its "World Urbanization Prospects" report defines megacities as urban agglomerations with over 10 million inhabitants. Reports from academics, the European Council, the Organisation for Economic Co-operation and Development delineate them as the metropolitan areas that are inhabited by more than a total population of 10 million people.

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