What's more interesting, is that somehow very few new nice areas (towns, cities) have been built. Take almost any area in London with anything built after the 1950s, and in many cases the new buildings make the area far worse, not better. Kensington is still the size it was, and there are hardly any new Kensingtons available - and a lot less affordable for an average professional.

London is wealthy enough for there to be no 'bad areas'.