The ideal city is a label for a perception in urban planning, where a place is designed on a drawing board according to coherent aspects, often connected to social-utopian ideas and an aesthetic aspiration. Constructs of urban planning that follow the dogma of framework are defined by lines and links that connect the single elements, and by relations established by the spatially dominating parts.

One of the forces forming structure in the organisation of urban space is the principle of minimising the effort for travel; the physical and mental effort of traversal is crucial. Built objects and the relations among themselves create a net which embraces the single elements. Space is formed by experience, realness and yearning, and yearning and realness can be in stark contrast to each other. Realness reveals the system boundary of a utopia. Yesterday's utopia collides with today's reality and therefore becomes verifiable. If a utopia does not pass this test, the space formed by a tried implementation of it loses its function, becomes abstract and finally vanishes. Public space that isn't used gets abstract, loses its meaning and finally becomes a fiction; fictions are not considered real. These fictional places are blind spots within the urban net.