Marina City was conceived in 1959 by architect Bertrand Goldberg as a “city within a city”; an impetus to ease the exodus of Chicago’s urban middle class to the suburbs. Occupying an entire central city block adjacent to the Chicago River, the mixed-use programme at Marina City efficiently grouped commerce, recreation and education at the lower levels of the city and placed housing above. “Living above the store”, as Goldberg called it, exploited the use of the land in the most efficient way. The buildings were constructed with concrete cast in-situ, a marked departure from the Miesian steel and glass rectilinear boxes populating Chicago in the 1950s and 60s. At the time of construction, the towers were the world’s tallest buildings built of reinforced concrete.