Kálvin square, located on the southern perimeter of the City, completely lost its former character after the Second World War: the square walls were replaced by war gaps and the space in between became a traffic junction. Development on the vacant parcels began after the change of regime in 1989; the first buildings were Hotel Korona and the blocks of Kálvin Center. The original plans for the office centre site were significantly modified due to the authorities' orders and regulations: the glass surfaces slanting towards the square disappeared, the reconstruction of a section of a palace designed by Miklós Ybl on the facade was not realized, and the roof of house No. 13 was cut off. The three glass blocks are however very unique and characteristic, which made them one of the most debated building ensembles of their era.