The construction work in Karlsruhe is a never ending story. Here today and not gone tomorrow, but simply in another spot. That's why the real Karlsruhe remains invisible and hidden to residents and visitors alike.
In fact, Karlsruhe should have been mentioned in Italo Calvino's post-modern novel Invisible Cities, perhaps as Carla Wilhelmina in chapter 11 "Hidden Cities".

P.S. The definition of post-modern means "beyond the modern post-office". A term that was originally coined in Karlsruhe (where else?) after the central post-office on Europe Square had been turned into a modern shopping mall.