Yet another example demonstrating the abundance of free space in the center of Berlin is the Potsdamer Platz.
Potsdamer Platz started as a trading post at the outskirts of Berlin to reach the status of the busiest traffic center in Europe and heart of Berlin's nightlife by 1920/30's. Then again, it got completely ruined during the last days of World War II and for many years it stayed totally desolate as the Berlin Wall cut it into halves. Wim Wenders movie Der Himmel über Berlin gives a good impression of the Potsdamer Platz at the time, if you are curios.
After the fall of the Wall Potsdamer Platz became "the biggest construction site" of modern Europe and within few years it turned into one of the biggest touristic attractions of Berlin.
History closes its circle - the Potsdamer Platz is once again a heart of Berlin's nightlife:
Spectacular roof of the Sony Center: