Otto Wagner Church or Steinhof Church, (Kirche am Steinhof) - also called the Church of St. Leopold, is the Roman Catholic oratory of the Steinhof Psychiatric Hospital in Vienna.
The building designed by Otto Wagner is considered one of the most important Art Nouveau churches in the world.

The church dedicated to Saint Leopold was built between 1903 and 1907 by the 63-year-old architect Otto Wagner, with mosaics and stained glass by Koloman Moser, and sculptural angels by Othmar Schimkowitz.

The copper-covered dome of this prime example of Viennese Art Nouveau architecture is visible from quite a distance, as the church stands high on the crest of the hill.

http://www.wikiwand.com/en/Kirche_am_Steinhof