Large dimensions: in and out of proportion - The "mega structure" just refers to itself and its dimensions are simply related to the relationship between economical and technological issues, while its vitality is supported by mobility flows. The large scale, both on the physical and on the conceptual side, asks to reflect about the traditional paradigms of urban and architectural design, but most of all about the new relationship occurring between planning strategies and architecture. Large size buildings are mainly located in the urban sprawl areas, with efficient infrastructures and weak urban fabric, where integration is quite difficult. Mega structures have always existed - monuments, public buildings or infrastructures - as every culture has raised its own monuments as a demonstration of power through an impressive possibility of dominion on nature, a continuous challenge of man.