The search for the ideal city has always permeated human history, constituting a utopia pursued by rulers, artists, philosophers, and, in more recent history, by us, urban planners. Since the 19th century, various models of ideal cities have been proposed—and, at times, built—ranging from Howard's garden cities to mechanized, radial, and walking cities (like those of the Archigram group), to nomadic ones like Constant Nieuwenhuis's New Babylon, and modernist cities, among others.
