The good thing about cities is they re-invent themselves. The bad thing about cities is, they reinvent themselves.
While world capitols like Paris and Rome are pretty careful with what they tear down, New York and Tokyo have always been less hesitant about replacing the old with the new. Manhattan's iconic Singer Building (the tallest skyscraper in the world, in the early 20th Century, photo on left) was torn down amidst much protest in the late 1960s.
Now Tokyo's similarly iconic Nakagin Capsule Tower, part of the Metabolist movement of the 1960s and '70s, is also going the way of all things. The modular structure will be going on the chopping block to make way for a newer structure. Debate, as you can see here, is heated.