Architectural megastructures evoke both fascination and discomfort. On the one hand, they embody typological experimentation and courage – on the other hand, their legacies and scale often lead to social, infrastructural, and financial burdens for municipalities. Nonetheless, as fixed landmarks in urban areas, they are shape a city’s identity. Berlin has its own, spectacular burdens: the visionary motorway construction Schlangenbader Straße, the dilapidated ICC, or the former Tempelhof Airport. Against this backdrop, we discuss transformation strategies at megascales with pioneer developers and conceptualists. How do we rethink and reactivate obsolete urban structures and monoliths?