The station at Karls-platz, on the original Viennese city line, is yet another building designed by the famous architect Otto Wagner (1841-1918) in pure Viennese Jugendstil, known as the secession style. The change to underground operation in the years 1976 to 1981 entailed a complete reconstruction of Karlsplatz station. The pavilions were to be removed in the course of the construction, but were renovated after protests and rebuilt two metres above the road level at the time.