The City Hall – City Government building on S. Radić Square, a protected cultural property, was built between 1956 and 1958 by architect Kazimir Ostrogović. At the peak of his creative career in the  50s, Ostrogović gets the opportunity to urbanistically design the central zone of the new administrative centre of Zagreb –  from the railway station in the north to the Sava River in the south. The first phase of this grandiose project was an urban-architectural competition in which a complete urban development of the new city centre was sought with an architectural solution for the building of the National Committee of the City of Zagreb. Urbanists Zdenko Kolacio and Zdenko Silla proposed a solution to extend Zrinjevac, a green longitudinal surface around which public buildings are placed, which spatially defines and shapes a free green belt that is supplemented with daily life content, restaurants, offices, cinemas, a museum and residential buildings on the edges that allow a gradual transition to neighbouring residential zones. Initially, it was conceived as a three-part complex with a congress hall, an administrative building for city services and an office skyscraper. In it are all five points of Le Corbusier’s New Architecture, with the addition of atriums that bring a large amount of natural light to the centre. The building floats above the park designed by landscape architect Mira Halambek-Wenzler.