This survey paper will deal with the form and possible explanations of Colombia's urban diversity; the conscious effort to encourage it which is taking place both in the national government and in the regions and cities themselves; with the international interest in the phenomenon and the supportive efforts which follow; and with the relatively sophisticated (fully in form and substantially in practice) structure of planning and administration for urban and regional development. An attempt is also made to evaluate the contribution which international agencies have made, or can make, in assisting Colombia to meet its problems of urban growth and the urban environment. Sections of this paper discuss: (1) Toward a True Urban Majority; (2) The Depth of Regionalism; (3) The Structure of Government--and the Cities; (4) Colombia's Urban Array; (5) The Action Agencies for Urban and Regional Development; (6) The Depth of Urban Skills; (7) The National Plan for Regional Development; (8) The Flavor of Cities; (9) Metropolitan Government--And Bogata; (10) Planning for Bogota; (11) The Housing Conditions of the Urban Poor; (12) Toward an Urban Reform Law; (13) International Assistance; (14) A Clash of Strategies. [For related documents in this series, see UD 013 731-732 and 013 734-744 for surveys of specific countries. For special studies analyzing urbanization in The Third World, see UD 013 745-UD 013 748.] (Authors/SB)