Tempelhof Mountain

(The storied Tempelhof Airport closed last October, and since then Berlin has wondered what to do with it. Architect Jakob Tigges has suggested building a “euphoric” 1,000-meter mountain, which would be partly ringed by the iconic Nazi terminal building. The proposal is not a serious idea, admits Tigges; rather, it's a provocation to use the site for something other than mediocre apartment buildings. Still, it would be a most unusual urban park, where instead of on an airplane, you ascend on foot. Image by Jakob Tigges and Malte Kloes.)