"Legacy" or "legacies" has been a key world in the recent history of the Olympic Games.
In fact, it is used by officials and administrators, including the International Olympic Committee, to convince host cities and the public that the Summer or Winter Games are not just one-time, expendable extravaganzas, but will contribute to leaving sustainable influences afterward.
And when they refer to Olympic legacies, this does not mean only infrastructure, like stadiums, arenas, buildings and parks, but also train lines and stations and highways that are newly built or renovated for the event.