This is the first book of a series about mega-event. Mega-events have multiple effects on the society, the environment, and the economy of a region. This can range from increasing leisure facilities for locals to better infrastructure, but also to economic growth. There are various approaches one has to take to arrive at the point where it is possible to conclude whether the impact of mega-events, like the Olympics, is truly as great as often argued. Having an extensive background in tourism we believe that tourism is the best indicator to see the results of mega-events. Obviously mega-events are not created because of tourism, but the relationship between them is undeniable. One can look at the number of tourists in the years before and after the event and compare them with the numbers of the event year. Further, one can look at the expenditure rates. All this needs to be looked at in the long and short run.