> Even in Friedrichstraße, which is a hype neighborhood with great amount of activity, you have hundreds of square meters completely unused, with wild plants gr

> Even in Friedrichstraße, which is a hype neighborhood with great amount of activity, you have hundreds of square meters completely unused, with wild plants growing around and random waste accumulating. Two things: I think you put too much value to Friedrichstraße, and likely Mitte in general. It is the physical and historic city centre, but that doesn't have the same meaning as it has in other cities. Second, in many parts in East-Berlin, you have a unclear ownership of houses and ground with competing claims. People have been disowned by the Nazis, Soviets, or by the GDR. The families have gone into diaspora and are partly spread over the world. Random people may have moved in and layed their own claim. The ownership is unclear and spread. And it is a battle to lay claim to your _part_ of ownership. The ground is gaining worth over time. All ingredients, which do not expedite the development of land.