Megalopolises designed in the third millennium, or metropolises marked by the many contradictions of modern development. Historic cities with a wealth of monuments or urban models still surrounded by wild nature. Today the cities of the five continents are the environment in which the majority of the planet's population is concentrated. Every city has its own style, its own model of life, its own horizon of reference, whether these are soaring skyscrapers, gothic spires, or endless residential neighborhoods. This volume and the splendid photographs accompanying it give an original and unusual view of the diverse forms and interpretations made for the inhabitable urban space, by architects, engineers, administrators, and simple inhabitants.