Karlsplatz Stadtbahn Station is a former station of the Viennese Stadtbahn. The buildings above ground on Karlsplatz are a well-known example of Jugendstil architecture. These buildings were included in The Vienna Secession, as they followed many of the artistic styles of that movement. They were designed by Otto Wagner, adviser to the Transport Commission in Vienna, and Joseph Maria Olbrich and are, unlike the other Stadtbahn stations, made of a steel framework with marble slabs mounted on the exterior.