Otto Wagner's Church of St. Leopold at Steinhof is one of the most important buildings in Vienna. Opened in 1907 and standing at the highest point of a sprawling psychiatric hospital complex, it was the first modern church built in Europe.

Wagner borrowed from European architectural history, from Byzantium to baroque to classicism. The design itself, however, is completely free of historical models, the ornamentation being consistently modern.

The cladding with marble slabs stood for an economical and hygienic type of architecture — a requirement that was also implemented inside, where the design was adapted to the needs of the patients.

Among the artistic highlights of the church’s spacious and bright interior are the glass mosaic windows by Koloman Moser. Together with other features designed by Otto Wagner and his studio, they form a unique ensemble of Viennese modernism.