Otto Wagner Church or Steinhof Church, (Kirche am Steinhof) - also called the Church of St. Leopold, was built between 1903 and 1907 by the 63-year-old architect Otto Wagner.
It is considered one of the most important Art Nouveau churches in the world.

Wagner enlisted many artists and artisans who were part of Vienna's Secessionist movement to help decorate the building.
The mosaics of the side altars are made by the painter and commercial artist Rudolf Jettmar (1869-1939).