Although cities are correctly considered as a complex phenomenon, they mainly constitute the main growth factor in the global economy as well as the main responsible to produce environmental pollution and social inequalities. To support this thesis, numerous researches argue that cities tend to compete to attract investments that are useful for growth and, in this way, try to strengthen their 'global identity'. For this reason, cities tend to host the so-called mega-events which undoubtedly bring enormous investments, evident urban transformations and various benefits. On the other hand, cities are very fragile, victims of climate change, natural risks and indiscriminate land consumption.