The Rotunde in Vienna was a building erected for the Weltausstellung 1873 Wien (the Vienna World Fair of 1873). The building was a partially covered circular steel construction, 84 m (approx. 275 ft) in height and 108 m (approx. 354 ft) in diameter. For almost one century (followed after its own destruction by an exhibition hall in Belgrade, 1957) it was the largest cupola construction in the world, larger than the Pantheon in Rome (diameter 43,4 m); built in 118–125. It was designed by Austrian architect Karl Freiherr von Hasenauer and built by the German company Johann Caspar Harkort of Duisburg.